The issue is if rare is simply "not many in circulation", that's very very different from rare being "it is a unique artifact". The former kind of rarity doesn't really present an existential end, whereas the latter does.

Yes this is disingenuous to the extreme.

My neighbor self-published a book, printed I think 100 copies at his own expense. It's literally a rare book. I can't imagine he nor anyone would care if an AI company bought a copy, no matter what they did with it.

Maybe these "rare books" are first edition Mark Twains, and. maybe they're unwanted books that would otherwise have gone to be pulped. The distinction is important and by not giving any evidence or even a qualitative claim about the types of books, 404 media is being pretty weak here.