This sounds terrible from a user perspective and arguably promotes certain types of music while penalizing others. As a user, if I hear more than a few songs that are terrible that were forced upon me by some algorithm, I am not going to listen to that playlist/use that service anymore. If users are the only way you are generating training data (for this supposed only self-published music world), you are going to end up with the music version of clickbait to get users' attention before they hit skip. I really cannot emphasize how bad optimizing for this would be for music.

Whatever your opinion on "current gatekeepers", some of them do provide valuable filtering services that I struggle to see how an algorithm could accurately replicate without compromising what makes music magical.

I think you could do this by pushing to users who tend to look for new artists already. There's a large set of folks that love to discover new music, and actively do so, and adding one or two new artists to promote here would be an easy way to start the network effect to other users.