As for input data to models, my intuition is that they would be tainted by the copyright of the input images. It's just that nobody has a bot for scanning AI models for their photographs, so you don't see a lot of litigation or DMCA takedown requests here. It's easy when someone just uploads your photo to their website. It's hard when the photo contributes some weights to a neural network.
My main takeaway is that copyright is very imperfect. It doesn't allow for any unsolicited enhancements of someone else's work.