I'm pretty sure the Jackson Estate doesn't have any legal legs to stand on (not only is this obviously parody, which is perfectly legal, but they don't even mention him directly). I think it was more of a request, which the devs took to heart. Think of it as a favour to MJ, to keep his family happy.
You're only really in breach of copyright if you try to pass other people's concepts off as your own, and even then it takes a lot of proof to convince most judges your idea was stolen.
You're only really in breach of copyright if you try to pass other people's concepts off as your own, and even then it takes a lot of proof to convince most judges your idea was stolen.