Private Maps, whether Survival or Creative, has been massively ignored during huge updates. Private Maps currently are bland and do not really hold much replayability besides roleplaying (creative), building (survival/creative), or having fun with friends (survival/creative).
I propose a huge mega update that would reshape Private Maps. This update would not remove anything, but adds tons of content to the game. My proposal is for commands to be added to the game. (Ex. tp, gamemode, etc.) and a command block. This would completely change the game as new maps would arise with minigames made by the community, and more player retention. A gamemode command would also help the game as there is no good way for an owner to actually switch gamemodes without paying 50 gems. I don't ask for commands that everyone can use, just the owner of the map.
I believe that this update would push the player count higher and higher, and introducing more opportunities for players to express their creativity in the game.