So I can have a giant database of all the most recent copyrighted works, on my home computer, as long as I claim I'm using it for training a model? And if I happen to listen to some music or watch some movies too, who's going to know?

I think an argument could be made that it's fine for an LLM to learn from copyrighted works, but maybe it should have to go to the library to do it. Having your own human-accessible copy of those works (at home, or at Meta), doesn't sound as acceptable to me.