it is not complicated, just some settings for the mapgen, but not from drunken admins, but from the users for the users.
your idea is also nice, much easier

idea:
vote for better maps in matchmaker eg. 3v3 due playersettings

buttons for color yellow(dust),green,red(eyecancer),white(eyecancer)

also buttons for shape settings:flat(open),flat(choke), water, setons-clone,...
buttons for small,mid,large..

majority wins and map will be generated, if you can not do it before generation, make an list with prefered setting on next map for the generator

best solution would be that only connected players vote for their map , not the whole waitingpool
the connection should be before map generation(i mean the 6 players in 3v3 should vote for their map)