You understand Warhol made essentially all of his post-illustration career income, during his own lifetime, from licensing and copyright? Including licensing his own identity.

We wouldn't even know who he was without it.

One could perhaps advance an argument that he wouldn't have wanted to be a posthumous brand (this might be stretching credulity) or have all the squabbles over his estate, but one cannot possibly use him as an avatar in an argument against copyright protection for living artists, because he essentially pioneered being a living famous licensed artist.