I agree with deepfakes are derivatives. You're using the likeness of someone whether visual or audio to highlight work. People pay attention because of that likeness. Weird Al asks for permission, video games have to pay royalties. So JayZ should have been asked permission in that sense.

If this was a parody, that could probably be argued very differently. Not sure where this particular case falls legally.

I don't agree with if you don't own the copyright you are infringing by publishing something the model produces. It should be tied back to the likeness of the original source.

The argument would be - if I never used any copyrighted JayZ sources (talking in a public setting, not giving a speech) and produced a deepfake, provably so, that would prevent me from being sued by JayZ & co?

Ideally no, because I'm still using his likeness to promote something.