It started with Leap of Faih being removed from Stream, because of a complaint of an artist that they didn't want their music featuring in pornography. If I understood correctly (and I'm not sure I did), apparently there's a term of service (in fine print) that the bought licence for music can't be used in a pornographic setting, among other things. Or an artist or agent can complain after the fact and demand the music be removed, so the game is banned from commercial platforms, for fear of litigation. This led other devs (Artemis, Chasing Sunsets etc) to try and replace the music for already released content, and try to find a solution for upcoming updates (e.g. no music at all).
My understanding is, and I repeat I may be wrong, as I'm not a lawyer or a native English speaker, that even if a dev has paid for a licence, it can be revoked afterwards if there's a complaint.
If anyone knows more about it, it would be much appreciated.