Suing over a copied style is a dead end for artists. Honestly, there are hundreds of artists in anime and manga who have all copied or been inspired by one another. If you go after entity, then honestly, you have to go after all of them, human or A.I. because of the ethics of copying a style is still stealing.

While Studio Ghibli does have a valid point about an A.I. reproduction be not original to them, what's to stop another artist from reproducing a work, and then someone sprout a lawsuit about the copy being A.I. and not hand drawn? You create a complete legal landscape and minefield by these lawsuits, and even then, you're hurting your own brand.

The best thing Ghibli should do is to actually contribute to ChatGPT with samples of work to teach the A.I. and then have a valid stake in things to say yea or nay to.

You don't bash the guy who takes your mousetrap and makes a better one. No... you buy into him, invest into him, and take a stake in the claim and make him say his work was derived from your original design, but you're now his investor and contributed to his work.