The Supreme Court is already side-eyeing attempts to construct copyright out of trademark ownership. Copyright law itself has a federal preemption clause, which itself was a reaction to states passing their own perpetual music recording ownership schemes, but would apply to any attempt to cobble together non-copyright claims into something that works like a copyright.
For example, states have "right of publicity" laws, but you cannot use them to overturn, say, the copyright interest that a paparazzi has in an unauthorized photo of you. Yes, there are literally court cases in which people have been photographed by paparazzi, reused the photo that the paparazzi took, and then were sued for doing so. Celebrities will counter-argue right of publicity, but federal copyright preemption dissolves those claims[0].
Furthermore, trademark law only specifically applies to source-identifying contexts. And the standard for confusing trademarks is lower than the standard for derivative works in copyright. A year from now when Mickey Mouse hits public domain, if I want to just use him in a book, that's not a trademark violation. If I want to put him on the cover, then that's a trademark violation - but only if the specific way I drew him looks like the trademarked Disney logo. If I were to draw, say, a hyper-detailed portrait painting of the mouse and put that on the cover, that would be obviously not identifying Disney as the source of the work and thus not a trademark violation.
Keep in mind: this is already happening with Winnie the Pooh. There's an indie filmmaker who is making an unlicensed horror movie where the cartoon bear is a murderer. Nevertheless, he has Winnie the Pooh in the title. Nobody is going to confuse this for a licensed Disney film, however, because the cartoon bear is a murderer.
[0] Yes, this also implies that the rights of artists trump the right of privacy in the US, at least when no other crimes are committed. In, say, France, this is the opposite: public photography requires permission from every person in the photograph, so photographing large crowds is about as legally risky as training an AI to draw with copyrighted images in the US.
For example, states have "right of publicity" laws, but you cannot use them to overturn, say, the copyright interest that a paparazzi has in an unauthorized photo of you. Yes, there are literally court cases in which people have been photographed by paparazzi, reused the photo that the paparazzi took, and then were sued for doing so. Celebrities will counter-argue right of publicity, but federal copyright preemption dissolves those claims[0].
Furthermore, trademark law only specifically applies to source-identifying contexts. And the standard for confusing trademarks is lower than the standard for derivative works in copyright. A year from now when Mickey Mouse hits public domain, if I want to just use him in a book, that's not a trademark violation. If I want to put him on the cover, then that's a trademark violation - but only if the specific way I drew him looks like the trademarked Disney logo. If I were to draw, say, a hyper-detailed portrait painting of the mouse and put that on the cover, that would be obviously not identifying Disney as the source of the work and thus not a trademark violation.
Keep in mind: this is already happening with Winnie the Pooh. There's an indie filmmaker who is making an unlicensed horror movie where the cartoon bear is a murderer. Nevertheless, he has Winnie the Pooh in the title. Nobody is going to confuse this for a licensed Disney film, however, because the cartoon bear is a murderer.
[0] Yes, this also implies that the rights of artists trump the right of privacy in the US, at least when no other crimes are committed. In, say, France, this is the opposite: public photography requires permission from every person in the photograph, so photographing large crowds is about as legally risky as training an AI to draw with copyrighted images in the US.