So at the bare minimum, a mechanism needs to be provided for retroactively removing works that would have been opted out of commercial usage if the option had been available and the rights holders had been informed about the commercial intentions of the project.
If you do this, you limit access to AI tools exclusively to big companies. They already employ enough artists to create a useful AI generator, they'll simply add that the artist agrees for their work to be used in training to the employment contract. After a while, the only people who have access to reasonably good AI is are those major corporations, and they'll leverage that to depress wages and control employees.
The WGA's idea that the direct output of an AI is uncopyrightable doesn't distort things so heavily in favor of Disney and Hasbro. It's also more legally actionable. You don't name Microsoft Word as the editor of a novel because you used spell check even if it corrected the spelling and grammar of every word. Naturally you don't name generative AI as an author or creator.
Though the above argument only really applies when you have strong unions willing to fight for workers, and with how gutted they are in the US, I don't think that will be the standard.