Imagine if that were true - a human artist couldn't create anything, because everything in the world around them is their training set!

I think it has to be a likeness test - if an average person would think its a real Jay-Z music video, then it's a derivative work. Don't muddy it with the implementation details of how it was made.

I suspect that would be an absolutely terrible standard in practice. I realize you specifically have deepfakes in mind, but consider that in more general terms those are outputs from a machine learning algorithm. Such outputs will inevitably fall on a continuum regarding the degree to which they resemble a distinctive art style, voice, personality, or other metric.

It seems unreasonable to me that it should be illegal to use arbitrary input data to train a NLP translation model or an image classifier. Farther along the spectrum of outputs, style transfer GANs don't seem like they should be a violation of the law. Should TWDNE really be against the law to host? (https://www.thiswaifudoesnotexist.net/) According to your proposed standard, it would be.

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.