If I turn a book into my publisher that reads like a Stephen King rip off, they aren't going to publish it with a disclaimer that says "No really, this isn't a rip-off, it just utilizes similar themes and settings!"
Gen Ai can protest all it likes, but saying you aren't ripping someone off doesn't mean you aren't. The only way it can actually not rip off an author it trained on would be to remove all author names from the meta-data *before* training, which they'd never do because then they couldn't sell their plagiarism machine to plagiarizers.