I agree that just labeling the AI-generated stuff *should* be enough, but I wonder if it really is enough. Yesterday someone sent me a video of Brian Cox describing some concept. Right in the text of the original post it said, "This video features an AI-generated voice for storytelling and educational purposes. It is not the real Brian Cox." So, fully disclosed, but it didn't stop people from forwarding it.
When I complained, the person who sent it to me said that the idea's interesting regardless of where it came from. Is it, though? Would you have bothered watching it if it was some unknown talking head with an anonymous AI voice? The presentation matters. The video used Brian Cox because he's smart, personable, and has a history of explaining difficult physics concepts in a manner most people can understand. People generally trust him in his area of expertise. Using his likeness in something he had nothing to do with is simply a dishonest way to ride his coattails, even if you do add a caption saying, "Not really Brian Cox". It's the academic world's version of stolen valor.
So in principle, I agree. Just marking something as AI-generated should be enough. In practice I fear it's going to be an asterisk and fine print so small people won't notice it, and even if they do the realism will trick their hindbrains into letting their guard down because it appears to be someone they trust.