retrofuturist wrote:My question relates to these "additions" and the fact the Abhidhamma community tends to accept these older additions as "official" (indeed, seemingly referring to them more in discussion than the original Abhidhamma Pitaka content itself) and whether they would in turn accept modern scholastic/experiential Abhidhamma analysis (by the likes of Mahasi Sayadaw, Bhikkhu Bodhi, Nina van Gorkom etc.) as "official" in the same way they might regards a Mahavihara analysis as official.
I'd say it depends on how much these new additions would reflect the truth. Truth as in the direct insight into these matters, or if there's no direct insight, then conformity with the Canon and (Mahavihara) commentaries. So, it's kind of the same situation as with the suttanata I think.
I've just attended a (live) abhidhamma discussion with a local group of people, and a lot of vocabulary they are using is quite different from what I'm used to on dsg or in the commentaries (at least those that I've read). But after a while it was possible to make the connections and see that these new terms were really just reflecting the same old things. In most cases that is, so there were a few instances that seemed a bit like a new rendering and new ideas, which I guess is normal for any group of people that meet regularly and develop their own quirks and vocabulary. That's why it's important to have something to fall back on as the bottom line, i.e. the canon and the commentaries.
retrofuturist wrote:In the Abhidhamma community, what differentiaties insights made 1000 or so years after the Buddha, versus those made 2500 years after the Buddha?
Not sure where you get the 1000 years. If we assume that Buddhaghosa and the entire Mahavihara school (to which we owe the existence of Theravada and the Pali canon today) didn't organize an elaborate conspiracy, then Buddhaghosa was only the editor and translator (not creator) of the Sinhala commentaries that were brought to Sri Lanka by arahat Mahinda (son of Asoka). So, even if you don't take the stance of some theravadins that commentaries themselves were recited at the first council as well, then the commentaries cannot be more than 200 or so years younger than the Buddha considering that Mahinda lived in the 3rd century BC I think.
retrofuturist wrote:Do commentarial forecasts on the decline of the Dhamma preclude modern insights as being inherently faulty compared to those of the elders?
I don't really know. I think that Abhidhammattha Sangaha was/is so widely accepted because it's truthful to what's in the abhidhamma pitaka and its commentaries at least. When it comes to more modern writers like Ledi Sayadaw for example, as far as I remember reading, some of his criticism of the commentaries were considered very controversial at the time and several works were written in response that were in turn critical of his findings. So, in situations like this, I think it's important to try and consider all sides of the argument (when possible because most of this stuff is in Burmese or Thai), regardless of whether some modern author is critical or putting forth new ideas about the abidhamma, suttanata, commentaries, etc. The more we can be aware of different views, the more chance I guess we have of not following someone's views blindly. Which of course is pretty much all one can do, since when there's a lack of direct insight, then the only other available option is reliance on views.
Best wishes