If AI-created art isn’t copyrightable then that means it’s public domain. But it’s entirely possible to create something that is copyrighted using public domain “raw materials”, you just need to do some work with it. And if those “raw materials” are never published, only the copyrighted final product, it’s going to be really hard for anyone else to make use of it. So I don’t really see how this is a big deal, especially not to Hollywood.