From what he says it almost sounds as if he prepared a game where you sign-up in secret and then in the game you don't even know who plays

Maybe all the game will be played via PMs and to keep the secrecy complete,
phantom will send all our PMs on the game thread as posts but we won't know who posted them... and then we are to deduce who the players are and also who of them is the wolf. Then I say "I vote Mac" and later we learn that Mac didn't even play in this game. Then people start to debate whether I voted Mac because I made a mistake or whether I am a wolf and intentionally wasted a vote. Wow, now that would be really innovative style of game
(No, I know it ain't funny, it's really like that, of course.)