Nibbana is an unconditioned dhamma, and is included in “sabbe dhamma anatta”.
When it's intended to be excluded, you will instead see "sabbe sankhara" instead of "sabbe dhamma". Therefore, "all compounds are devoid of self" would be "sabbe sankhara anatta". Therefore, they are different in meaning and intent. Is the person you quoted suggesting they are synonymous?
(...although interestingly it seems that in the different editions of the Pali Dhammapada there are discrepencies about which ones are used when).
“I hope, Anuruddha, that you are all living in concord, with mutual appreciation, without disputing, blending like milk and water, viewing each other with kindly eyes.” (MN 31)
What is the final conviction that comes when radical attention is razor-edge sharp? That the object of the mind is mind-made (manomaya). (Ven. Ñāṇananda)
"If you have always believed that everyone should play by the same rules and be judged by the same standards, that would have gotten you labeled a radical 50 years ago, a liberal 25 years ago and a racist today." (Thomas Sowell)