The cameos of A Community X-Mas are inaccurate. In fact, the game's writers specifically state this at the game's opening. And so, an obvious question arises:
Why make a cameo game with inaccurate cameos? Doesn't that miss the point?
This becomes even more of a problem due to the nature of ACX-M's gameplay. Much of gameo consists of walking around and talking to the cameo objects. There's a mystery plotline tying everything together, and a refreshingly different endgame, but the majority of the game still consists of wandering around talking to people whose names you recognize. When the names don't match the personalities, the game naturally feels flat.
This is a puzzle to me. Why take an excellent premise ("ZZTers are trapped in a palatial chalet in the snow, and begin disappearing one by one. Whodunit?") and then rob it of its charm by leaving out the one thing that would make it really compelling: the personalities? Why throw away the chance to make people actually interested in finding out whether or not their persona is the villain? There's an astounding amount of wasted opportunity here.
On the other hand, ACX-M would be a decent ZZT game even if all the recognizable names were discarded. There are some amusing bits, the whole game is very nicely illustrated, and the Rube Goldberg sequence in the endgame is particularly clever.
Summary: Forget trying to associate the characters with their online personas, and just act as if ACX-M didn't contain anybody you knew. In those circumstances, it's actually pretty entertaining.