If these people create real music, "fake" seems like the wrong adjective. It's very common for musicians to be involved in a bunch of different bands, or even for the same group of people to release music under different band names, for when they want to experiment with stuff that isn't their normal band's "brand". What's being described sounds like SEO optimization to me. A recent Reply All episode interviewed someone who is very successful at Spotify SEO: https://gimletmedia.com/shows/reply-all/j4he7lv