An10.6 definition of nibbāna.
‘This is peaceful; this is sublime—that is, the stilling of all activities, the letting go of all attachments, the ending of craving, fading away, cessation, extinguishment.’
‘etaṁ santaṁ etaṁ paṇītaṁ yadidaṁ sabbasaṅkhārasamatho sabbūpadhipaṭinissaggo taṇhākkhayo virāgo nirodho nibbānan’ti.
This reddit post should make clear my position.
When EBT first break away from the classical theravada and commentaries, there’s some people who have eternalistic tendancies and wishes to have something, anything which last forever after death of arahant. So they read the suttas alone (without commentaries, or ignoring commentaries) and come out with their various views on it. Some maybe also influenced by Mahāyāna thinking.
Some of the possible views of what remains after death of arahant includes: consciousness unestablished (this is reification of what shouldn’t be interpreted positively), Nibbāna itself (denying that after death of arahant there is nothing) Bhikkhu Bodhi on Nibbāna - #621 by NgXinZhao, dhammakāya (most if not all of Mahāyāna) See Burg’s comment on it, etc.
Mahāyāna view is likely mistaken a state of very blissful samādhi with nibbāna. Very suspect would be any notion of the lines of: experience itself is not inherently dukkha, but desire makes it so (championed by @yeshe.tenley) That they try to open the way to something as nibbāna, but I defeated it in here. What is dukkha? - #39 by NgXinZhao It also fits in their desire to continue to be reborn again and again to become a bodhisattva and then Buddha. So they actively are avoiding the nothing after parinibbāna type of attainment. Not too hard if one holds onto wrong view.
Also a great factor contributing to the confusion is that different very famous and highly regarded teachers seems to be leaning in one way or another on this issue. Followers of theirs who didn’t read the sutta first, does use the lens of these theories to read the suttas afterwards and it’s very hard to change the views once people got fixed on one side or another.
Nothing after parinibbāna camp: classical theravada, Ajahn Brahm, Bhante Aggacitta etc.
Something after parinibbāna camp: (I have heard) a lot of Thai Ajahns (I dunno which, I generally don’t read their books, but I know B. Thanissaro is in here), most of Mahāyāna (I have a mahāyāna Bhikkhu friend of over 10 vassa, well learned, he confirmed nothing after parinibbāna is unacceptable to him). Famous Mahāyāna teacher in this include Alan Wallace (I have been to his retreats and he said explicitly he doesn’t believe in nothing after parinibbāna), Thich Nhat Hanh (Read one of his serious commentary on sutta book, very painful to filter out his views from the dhamma), etc.