To be honest, they have a build team for a reason. I'd honestly just leave it to the build team, just like we leave developing updates to the developers.
I think it's pretty safe to say that majority of the map submissions are all going to be the same stale map shape that most games have, along with a playing style that really doesn't fit Cube. Aside from that, I can imagine that probably almost all of them are going to be for Skywars, and then people start making them for Eggwars, then for lucky islands, and so on so forth. The popular games will get all of the submissions, and lot's of them probably wouldn't come near the expectations that the current build team has. Adding community made maps seems cool and all, but I honestly doubt there are going to be a few, if any, good maps that don't require lot's of editing.