Do you have a reason to believe this ain't already being done? I would assume that the big guys like openai are already training on basically all text in existence.
https://torrentfreak.com/meta-torrented-over-81-tb-of-data-t...
I doubt they'd resort to piracy for what is basically the same information as what they've already legally acquired...
But here, Google isn't a license holder. Google doesn't license the text in Google Books (unless something has changed since the lawsuits). Google simply legally acquires (buys, borrows, etc) a copy of the book and does things with it that the US courts have found are fair use and require no license.
Incidentally I believe the French courts disagreed and fined them half a million dollars or so and ordered them to stop in France.
https://www.forbes.com/sites/danpontefract/2025/03/25/author...