I can see where Alberto is coming from but I agree, it's hard to argue moralities on a pirating site. My only worry regarding AI art is the potential to discourage the original artists from continuing. I know distributing paid art and AI art in someone's style for free is two sides of the same coin but I digress. I just don't want to see an artist give it up because of AI.
If however, the artist has already given it up, or has passed I say it's fair game. An example of this would be Jlullaby, fairly certain he won't ever be coming back and I know people are already making AI art from his stuff which is nice to see. For me as long as it doesn't cause someone to call it quits I don't see an issue. If I was a game developer, I'd freely post my stuff here and use it as advertising. It's going to get leaked anyway so why fight it.