I see AI training on public material like I would upcoming artists being inspired by the artists before them. Obviously the scale is very different. I don't mind your scenario because an AI firm, if they couldn't stay on top of what their model was creating, could voluntarily reduce the material used to train it.

You imply that AI model is creating new works and not merely rearranging pieces from other works you never saw and therefore might consider novel. AI model is not a model of a creative human currently: a human doesn't need to listen to million songs to create his own.