For "live viewing":
I imagine the original plan is for it to work like this:
Proctor (MMOG Staff member) will shout/whisper/whatever to call for the participants, make a locked room, then whisper the participants the password. They would then proceed with the match.
I feel the participants should have an option to get the proctor to unlock the room (leaving it as 1v1 city, of course) once everyone is ready so that 19 people (not counting the proctor) can watch the match. Of course, if one participant doesn't want other people to watch, then the room should remain locked.