What I don’t like is that when you deep-fake a CGI creation, the mouth still doesn’t work, because the base you’re working from is fundamentally wrong. So you have the images of a real person trying to match the incorrect mouth movements of a digital recreation of that person. The deep-fakes of Carrie Fisher over CGI Leia have the same problem. Leia may look a little more realistic (only a little) and then she mouths the word “Hope” and suddenly she’s an effect.
I think it might be possible for someone to (using a feathered mask of sorts) plop down the original mouth on top of the deepfake.