"Once the Big 12 was saved and the Pac-10 only expanded by two, the BCS no longer had any need to deal with the MWC."
Before this, it sounds like the BCS was motivated to get rid of the Non-AQ Boise-types messing things up, and appeasing congress by working the MWC into the BCS. Thus, I don't see why securing the Big 12 and Pac-10 but leaving a Boise state in the non-AQ MWC would be related.