To be clear, I'm not saying that you can't create Mickey Mouse images that are transformative (or that Disney might not bother suing over; I think there'd be a lawsuit if the Simpsons tried making a commercial film following the adventures of their rendition of Mickey Mouse).

Also, that usage of Mickey Mouse might be copyright infringing, but fall under fair use (probably parody), which is a specific defense of copyright infringement (similar to "self defense").

What I am saying is that:

1) If your model returns images which look near-identical to your training data, then any copyright infringement that applies to the training image will also apply to your image.

2) If your model can consistently return copyrighted imagery, there's little difference between explicitly sharing those images (with a password) and implicitly sharing them (via a model + prompt).