Why not add all unavailable brawl maps and older maps to game center?

For some time i have been questioning why the devs still havent added more older brawl maps like “Warriors path”, “river light house”, “mountain village” and some other maps to the game center for is to play in or explore. Even some other maps like “dead city”, “high cathedral” and “desolate town” were all maps used in the helicopter mode. But when next step missions came in they completely removed these maps without a announcement. It would be nice to see these maps be accessible in Game Center for ppl like me to explore them or fight in