no his contract didnt expire he asked for a release bc his wife and got it while he was in middle of feuding with orton. remember few months prior him and sabu caught that weed charge and that put rvd in shitter with vince they even took the belt off him and suspended him a month
You can google RVD contract expiring 2007, there's a ton of articles about it and some even talk about John Lauranitis actually being in the dog house at the time for failing to re-sign him.
I doubt if he was in the shitter he wouldn't have had matches with Vince on TV right before leaving and he wouldn't have went out with a win against Orton and he wouldn't have been invited to the 2009 Rumble.