IMO people doing it on their own for fun/expression is different than corporations doing it for profit, and there's no real way to stop that. I think if famous AI constructs become part of big media productions, it will come with a constructed moral justification for it. The system will basically internalize and commodify the repulsion to itself exploiting the likeness of dead (or alive) actors. This could be media that blurs the line and proports to ask "deep questions" about exploiting people, while exploiting people as a sort of intentional irony. Or it will be more like a moral appeal to sentimentality, "in honor of their legacy we are exploiting their image, some proceeds will support causes they cared about, we are doing this to spread awareness, the issue they are representing are too important, they would have loved this project, we've worked closely with their estate." Eventually there's going to be a film like this, complete with teary-eyed behind-the-scenes interviews about how emotional it was to reproduce the likeness of the actor and what an honor it was. As soon as the moral justification can be made and the actor's image can be constructed just well enough. People will go see it so they can comment on what they thought about it and take part in the cultural moment.