If you put your own work into generative AI and have it modify it, what comes out is a hybrid of your art and the many, many stolen pieces of art that were used to train the AI. That's a fact. That's how the AI works. The thing that comes out of it is NOT your work.
You have the right to modify your own work, but if you modify your work by blending it with stolen stuff, then the result is a derivative of this stolen stuff. And you do not, in fact, have a right to do that without being accused of stealing.