I don't know if it should be allowed.
Say I create a map, it has a few flaws when it goes public, and for whatever reason, I go inactive.
I wouldn't want anyone to mess with my map, unless I give specific instruction to certain individuals, and if it's within the possibility, give them my account and password so they can fix it.
I wouldn't want to come back after 6 months of inattentiveness to find that something I worked hard on have been completely and utterly destroyed, because what I saw and did, someone didn't agree on.
Take a very good example, my map: http://warlight.net/Map?ID=11104
have a very specific, and sometimes confusing, connections, but it's made as I think it should be, it have a few minor flaws, that I will correct when I get the time and energy.
Say I go inactive because I get hit by a car, after X amount of time, someone can "correct" what he think is the missing connections (there are no missing connections) and mess it up completely.
If it's for map that aren't currently public, I can see the use, but not something I'd want anyone to do to my maps.