Deepfakes have already been to the supreme court (see Hustler v. Falwell). Cutting back on such uses risks cutting deeply into freedom of speech. As with Falwell, the answers involve educating the public so that they can tell fake from real, not giving famous people the ability to blackball every work they feel too similar to themselves. Lots of people talk like Stephen Fry. He doesnt get to own that accent or mode of speech just because he is the most famous any more than Lindsay Lohan can own blonde valley girl (she sued gta V over that image).