It wasn't clear what's going on. How do they know the works were downloaded from a pirate site? Is there a whistleblower? AI's can read and understand text from physical books- they scan it. Whose to say the AI wasn't fed books that were purchased.

If corporations can be considered people, I don't see how you could legally prevent an AI from reading and learning from books that are available to the public.

It they aren't reproducing passages verbatim, how can it be a copywrite infringement?

It would be hard to prove but an AI can be taught to write in the "style" of an established author. (I'm sure humans do that too even if they aren't aware of it.)

I asked Bing one time to create paintings in the style of Van Gogh and Dali. It did quite well.