I don't have a lot of details (because paywalls) about the latest ebooks pornocalypse, but it appears that Barnes & Noble is telling everybody who currently has the power to list ebooks in their distribution system (except of course the major publishers, who are exempt) to remove the erotica titles or else:
https://www.erosblog.com/2024/08/17/pornocalypse-comes-to-barnes-noble/