We don’t know why individual songs were replaced, but they were clearly good enough for them to stay in the Sonic 3 that we got. They also stuck around for Sonic 3 Limited Edition (cancelled), if I’m not mistaken. Additionally, I don’t believe it’s entirely the case that people who don’t think the tracks fit are just used to the ones we actually got. I think Launch Base Zone’s proto music starting off very upbeat, and sounding a bit like circus music is bizarre. It makes me wonder whether there was originally some link between Carnival Night and Launch Base, but evidence says completely otherwise. I think this is one part that’s just not fitting at all and I don’t think was necessarily a completed track. Interestingly, the Launch Base proto music is also more fitting when it’s with S3&K, because it then doesn’t need to sound like a more serious end level.