I would say yes. His teachings have been appropriated by anti realists and subjective idealists. But, originally were not dramatically different from the suttas.
Both Chandrakirti (considered one of the highest ancient authorities on Madhyamaka by modern Buddhist colleges, see below) and Jay Garfield (highly respected modern Nagarjuna scholar) agree Nagarjuna did not teach that everything is imaginary, nor that objective reality does not exist or that external reality does not exist (either deliberately or inadvertently, all of these immensely reify the mind), nor that nothing exists, which are the most common misrepresentations of Nagarjuna.
Chandrakirti's works include the Prasannapadā—Sanskrit for "clear words"—a commentary on Nāgārjuna's Mūlamadhyamakakārikā and the Madhyamakāvatāra (his supplement to Nagarjuna's text) and its auto-commentary. The Madhyamakāvatāra is used as the main sourcebook by most of the Tibetan monastic colleges in their studies of śūnyatā "emptiness" and the philosophy of the Madhyamaka school. -Wiki page on Chandrakirti
34. Like a dream, like an illusion, Like a city of Gandharvas, So have arising, abiding, And ceasing been explained. This chapter thus brings the first principal section of Mulamadhyamakakarika to a close, drawing together the threads spun in the earlier chapters to produce a thorough demonstration of the emptiness of the conventional phenomenal world. Having demon- strated the emptiness of conditions and their relations to their effects, change and impermanence, the elements, the aggregates, 56 and characteristics and their bases — in short, of all the fundamental Buddhist categories of analysis and explanation— Nagarjuna has now considered the totality they determine— dependent arising itself and the entire dependently arisen phenomenal world- 56. Sometimes translated as “heaps,” or “collections.” These are the groups of more basic phenomena into which complex phenomena such as persons are decom- posed in analysis. The decomposition is in principle bottomless — bundles of bundles of bundles. . . . See Chapters III and IV. Examination of the Conditioned 177 arguing that dependent arising and what is dependently arisen are themselves empty of inherent existence. This is a deep result. It again presages the doctrine of the emptiness of emptiness that is made explicit in Chapter XXIV, and it develops further the theme explored in Chapter I, namely, that when from the Madhyamika perspective one asserts that a thing is empty or that it is dependently arisen, one is not contrasting their status with the status of some other things that are inherently existent. Nor is one asserting that they are merely dependent on some more fundamental independent thing. Nor is one asserting that instead of having an independent essence things have as their essence dependence or emptiness, either or both of which exist in some other way. Rather, as far as one analyzes, one finds only dependence, relativity, and emptiness, and their dependence, relativity, and emptiness. But this is not to say either that emptiness, dependent arising or conventional phenomena are nonexistent — that they are hallucinations. Indeed it is to say the opposite. For the upshot of this critical analysis is that existence itself must be reconceived. What is said to be “like a dream, like an illusion” is their existence in the mode in which they are ordinarily perceived/conceived — as inherently existent. Inherent existence simply is an incoherent notion . 57 The only sense that “existence” can be given is a conventional, relative sense. And in demonstrating that phenomena have exactly that kind of existence and that dependent arising has exactly that kind of existence, we recover the existence of phenomenal reality in the context of emptiness.
-Jay Garfield, Fundamental Wisdom of the Middle Way, VII.56
So people think Nagarjuna proves them right in their radical understanding of Buddhism as an anti realist or "all is imaginary" teaching and disproves the orthodox Theravada, but it's actually the exact opposite.
By reason of the cessation of one factor in the twelvefold chain, another successor factor fails to arise. Thus does this entire mass of suffering completely cease.
-MKK 26.12 Commentary by Jay Garfield:
23. If suffering had an essence,
Its cessation would not exist.
So if an essence is posited,
One denies cessation.
Similarly, the third noble truth is the truth of cessation. But inherently existent things cannot cease. Empty ones can. Nagarjuna’s
analysis thus explains the third truth; the reifier contradicts it.
24. If the path had an essence,
Cultivation would not be appropriate.
If this path is indeed cultivated,
It cannot have an essence.
25. If suffering, arising, and
Ceasing are nonexistent,
By what path could one seek
To obtain the cessation of suffering?
The fourth truth is the truth of the path. Again, the path only
makes sense, and cultivation of the path is only possible, if suffer-
ing is impermanent and alleviable and if the nature of mind is
empty and hence malleable. The path, after all, is a path from
suffering and to awakening. If the former cannot cease and the
latter does not depend on cultivation, the path is nonexistent. But
it is the analysis in terms of emptiness that makes this coherent. An
analysis on which either the phenomena were inherently existent
or on which emptiness was and the phenomena were therefore
nonexistent would make nonsense of the Four Noble Truths.
Chandrakirti found it acceptable to make firm statements about what exists conventionally. See below for many quotes of Chandrakirti on this issue, and please be aware that his arguments apply to both positions of the "mind only" school; the position that mind exists and all is mind, and the position that mind does not exist and all is mind. No matter how you slice it, Chandrakirti's understanding does not allow for "all is mind" or any similar idea to be a correct statement. To sum up this issue:
According to Nagarjuna and classical Madhyamaka, neither mind nor matter exist ultimately, and conventionally both exist. Therefore it is always incorrect to say that things are imaginary.
Saying conventionally matter is mind is incorrect because conventionally both are real. Saying ultimately matter is mind is incorrect because ultimately neither exist.
Chandrakirti quotes:
Some selections from a relevant work translated by C. W. Huntington, Jr. (Vijnanavada is the Yogacara or Mind Only school):
Candrakirti's Madhyamakavatarabhasya 6.86-97
A Madhyamaka Critique of Vijnanavada Views of Consciousness
C. W. Huntington, Jr.
The word “only” has no capacity to negate the objective component of knowledge (jneya).
“(87)...the Lankavatara sutra substitutes "mind alone" for "mind alone is preeminent in the context of everyday experience." The meaning of this scripture is not to be understood as a negation of form.”
...When the scripture says "mind alone exists; form does not," this is taught to deny the importance of form and so forth, not to negate their very existence....
(88) If he intended to deny the existence of objective reality wen he said that [the world] is mind alone, then why would the mahatma declare, in the same text, that mind is produced from delusion (moha) and volitional action (karman)?
What sensible person would look at a passage from this same [Dasabhumikasutra] and imagine that consciousness exists as an independent thing (vastutah)? A notion like this is nothing more than dogmatic opinion. It follows that the expression "mind only" serves only to clarify that mind is the most significant element [in experience] This text should not be understood to assert that there is no objective form (rupa).
(90a-b) Even though objective form does indeed exist, it is not, like mind, an agent
This means that objective form is inert.
(90c-d) Therefore, denying any other agent besides mind is not the same as negating objective form altogether.
Some people take (the Samkhya) idea of "matter" (pradhana) and such things as agent, others believe it is mind, but everyone agrees that objective form is not an agent. To prevent pradhana and so forth from being taken as agent, it is explained that they do not have any such characteristic. Seeing that it has the capacity to serve as agent, one declares that mind alone is the agent, and in doing so one gains the high ground in any debate concerning the agency of pradhana and so forth. It is as if two kings desire power in a single land, and one of the two rivals is expelled while the other assumes control of the country. No matter who wins, the citizens are indispensable and would suffer no harm. So it is here, because objective form is indispensable to both, it suffers no loss. One can certainly maintain that objective form exists. Therefore, continuing in the same manner, the text declares:
(91) Within the context of everyday affairs, all five psychophysical constituents taken for granted in the world do exist. However, none of the five appears to a yogi who pursues illuminating knowledge of reality.
Therefore, seeing as this is so,
(92a-b) If form does not exist, then do not cling to the existence of mind; and if mind exists, then do not cling to the nonexistence of form.
When, for some reason, one does not admit the existence of form, then the existence of both is equally unreasonable and one must admit the nonexistence of mind, as well. And when one admits the existence of mind, then it is necessary to admit the existence of form, for both are conventionally real.
"O Subhuti, objective form is empty of inherent existence." The same is said concerning the others, including consciousness. This is established both in scripture and through recourse to reason.
(93a-b) You destroy the relationship of the two truths, and even then your "real thing" (vastu) [i.e. mind] is not established, because it has been refuted.
In arguing that consciousness alone exists, without objective form, you destroy the relationship between conventional and ultimate truth as it has been explained. And even when you have destroyed this relationship between the two truths, your absolute reality will not be established. Why not? Once the reality [of form] is denied, your efforts [to establish consciousness] are pointless.
(93c-d) It would be better to hold, in conformity with this relationship, that in reality nothing arises; the arising of things is merely conventional.
(94a-b) Where a scripture declares that there is no external object and that mind (citta) alone appears as various things,
This scripture requires interpretation:
(94c-d) the refutation of form is provisional, directed specifically at those who are overly attached to it.
The meaning of such a text is strictly provisional. There are those who have lost themselves in clinging or anger or pride that is rooted in an extreme attachment to form; such people commit grievous errors and fail to cultivate merit or understanding. It is for these people, who are clinging, that the Blessed One taught "mind alone" even though it is not actually so. He did this in order to destroy the afflictions that are rooted in material form.
But how do you know this scripture is provisional, and not definitive?
Through both textual evidence and reason. The master has said precisely this:
(95a-b) The master has said that this [scripture] is of strictly provisional meaning; reason [as well] dictates it is of provisional meaning.
Not only is this scripture of provisional meaning, but also
(95c-d) This text makes it clear that other scriptures of this type are of provisional meaning.
And if one inquires which scriptures are of “of this type,” there is the following passage from the Sandhinirmocanasutra, explaining the “three natures”-the imaginary, the dependent, and the perfected:
The imaginary is nonexistent, only what is dependent exists.
(96) The Buddhas teach that the subject, or knower (jnatr), may easily be dispensed with once the object of knowledge, or the known (jneya), is no longer present. For this reason they begin by refuting the object of knowledge, for, when it is no longer present, refutation of the subject is already accomplished.
And so, the two main misrepresentations of Nagarjuna as presented by many Mahayanists (1. all is imaginary and objective or external reality does not exist and 2. nothing exists) are shown to be just that; misrepresentations.
So, classical Theravadins are at odds with the Mahayana "all is mind" or "nothing exists" misinterpretations of Nagarjuna, but wouldn't argue with actual Nagarjuna on the point that, for example, dhammas exist as dependently originated objects, but do not exist as ultimate self created eternal entities.
Nagarjuna taught that things exist conventionally, as dependent and so empty things, but do not exist as ultimate, self existent, eternal objects.
He was refuting Sarvastivadin doctrine and others that taught things like them. The Theravada would probably refute them on similar grounds.
Sarvāstivāda is a Sanskrit term that can be glossed as: "the theory of all exists". The Sarvāstivāda argued that all dharmas exist in the past, present and future, the "three times".
-wiki page on Sarvastivada
Nagarjuna's dialectic of universal negation was primarily directed to the Hinayana (Sarvastivadin) view that "all dharmas (things) exist,"
-Shunyata and the Vow-Power by Zuio H. Inagaki
November, 2000
Assume all of my words on dhamma could be incorrect. Seek an arahant for truth.
"If we base ourselves on the Pali Nikayas, then we should be compelled to conclude that Buddhism is realistic. There is no explicit denial anywhere of the external world. Nor is there any positive evidence to show that the world is mind-made or simply a projection of subjective thoughts. That Buddhism recognizes the extra-mental existence of matter and the external world is clearly suggested by the texts. Throughout the discourses it is the language of realism that one encounters.
-Y. Karunadasa