Apparently, Vince McMahon was absent from Monday's RAW taping because he was busy getting ready for some announcements this Wednesday about the soon to be relaunched XFL. The league will be announcing the teams and logos we can expect to see in action during a press conference that will be streamed on a number of sites, including XFL.com and ESPN.
As of right now, the league is currently signing players and details on those should be revealed in the coming weeks.
It's become fairly common for McMahon to miss RAW in recent months and he's often absent from SmackDown Live. However, he's well aware of what's going on and often gives instructions from home or whether he is on the road.
With Paul Heyman serving as RAW's Executive Director, Vince is obviously free to focus on things like the XFL.