I saw it here a couple months ago. The results so far were quite odd but it's early days. I'm not sure what the ethics are. My understanding is that models/actors of consenting age are now well treated in the industry. I'm not sire what those people will do if replaced. But that is true of uber and truck drivers when they figure out self driving, or me when copilot gets a lot better.

As for those not considered capable of consent? Maybe this decreases the pressure to hurt more of those people? But the ethics of training seem hidiously evil to me.