> Except probably Kosovo, which was not part of serbo-croatian linguistic space.

The Albanian speaking countries really punch above their weight for English language pop stars with global presence. ~7.5 Million Albanian speakers globally gave us Bebe Rexha, Dua Lipa, Ava Max, and Rita Ora. 22 Million Romanian speakers for a comparable post-Communist community and I don't think I know any pop stars with that background off the top of my head.