Ugh, that is the type of free-speech infringement that people should be worried about, not all this stuff about how YouTube taking down videos is government censorship.
A really good deepfake is still fiction. Really good writing is fiction. Really poorly-written fake "news" blogs "reporting" lies as truth is fiction. These are all allowed to exist (in the USA) because of the 1st Amendment. It is the price that we pay for living in a free society, that the government cannot tell you "your fiction is not allowed."
Textual accounts of real events, and lies about real events, have existed for ages. Sometimes the lies are more convincing than the truth. Audio recording and doctored audio has existed for ages. Photography and doctored photos have existed for ages. Video recording and doctored video has existed for ages. We'll survive another flavor of doctoring just fine without the government's help.