I've noticed Mcprohosting has done this, I'm not saying copy everything from them but this would be an awesome addition. I was so convinced into buying a server from them, but I didn't. So basically they allow you to pick a custom map, when you buy a server, I'd think hosthorde should do something like this, just my thoughts.
They basically copied it from Realms . We were discussing a similar feature internally, but I don't have any timetable for it being made and released.