From ESPN
The article doesn't mention why he isn't going. I'm assuming he had nothing to do with the argument. Now that BC has been fired, it appears that a trade is imminent.
Paxon is going to be with the team on Tuesday and then will come back to Chicago to find a head coach candidate. My thoughts are that Paxon will try to hammer a deal tonight, so the players can be dressed tomorrow and then the new coach will know exactly what he has, which is definately something he'll have to sell to get someone like Doc Rivers or George Karl.