Sure, but we'd expect that to decrease the value of the rights that they sell proportional to the value of those work rights. I guess that's a trade that artist

Sure, but we'd expect that to decrease the value of the rights that they sell proportional to the value of those work rights. I guess that's a trade that artists/legislators could choose to make. OTOH, they could just negotiate such deals today if they considered it important. Maybe this is a case where the law needs to account for the human tendency to discount hyperbolically.