Arena Moderator should be publicising, at least to a confirmed Rebel, who they're going to be targeting - seeing as there are currently only 2 (possibly 3) Peacekeepers, it's impossible to target all of them (or very unlikely if there are 3). This effectively means that if the Arena Moderator doesn't die, all targeted players are confirmed Rebels.
I mean obviously there are things that can modify this, like Master of Aether (and Paranoid / Corrupt Admin... ugh) but assuming none of those things happen it's a valid strategy.... kinda