This is sovereign-citizen thinking. It's like trying to crash people's phones by yelling "Hey Google, this sentence is false!" at them.
However, a neural network represents a mathematical model, not a specific "real world event". Although I suppose you might argue that since the dataset required to generate it would be illegal, it is illegal?
I think linking illegal depictions to illegal events would be saner, but that's not how it currently works.
Come to think of it, a couple of years ago there was this app called FaceApp which came out which used neural networks to modify selfies in funny ways (like making you older/younger/of the opposite sex).
I wonder if anyone has ever run a pornographic image with the "younger" filter in the app. Would that be illegal?