If copyright isn't retained you have absolutely no rights relating to copyright. You can't make someone do something by writing a line in a contract they don't have to follow.
However, it might stop some people from doing it anyway.
GPL allows you to attach additional permission notices and require them to be carried downstream. This is often used to carry MIT license notices when MIT software is used inside GPL, but you could also put something about how AI violates copyright if it's a "reasonable legal notice"...