This is a strong argument and gave me pause. I think if Disney sued they could probably win.
However - examples such as this are probably quite rare. Mickey Mouse is so uniquitous that is massively overrepresented in the training and data and that has resulted in overfitting. For the vast majority of artists and almost certainly for the plaintiffs in this case, the demonstration wouldn't work. You most likely cannot produce an infringing image from a concise text prompt.
Arguably one of the outcomes of legal action might be the need for a lot of effort to remove examples similar to the Mickey Mouse example. This would be a good thing but wouldn't prevent AI image generation from broadly doing the things that the plaintiffs want to stop it doing.
> (2) but I'd need to see how you show that "it does so to exactly the same degree".
Not sure I follow? If I produce an infringing image and a court agrees it's infringing then I'm liable. It doesn't matter how the image was produced. I don't see what there is to dispute here?