Some nuances here. There’s a variety of different roadblocks at different levels that will work to prevent pure AI slop books ever turning up in a typical public library of physical printed works; I think they never will.

Probably a handful of books in such libraries already have some text in them where the author has tried to pass off fragments of LLM-generated prose as their own and have got that past editors, reviewers and publishers, and that will sadly get worse.