This is a good thing to a point, right? They sell heaps of stock, some old / outdated stock (like "Pass Your Driving Test, 2018 Edition" as per the article), in bulk, at full price, no questions asked. Retailer's dreams come true.
(I don't believe them being digitized for consumption by AI will impact book sales much, as ebooks, google books, project gutenberg, etc didn't either)
It's great for the retailer, although I think that example was picked out because it's an extreme example of a book that'll never sell. But the volume of these orders shows another way the AI companies are pissing away their investors' money.
As long as the AI devouring a book isn't making it harder for a person to get access to a copy of the book. There might not be many copies of some out-of-print books.