Had Mesa voted yes, that yes vote would have been used as a hammer to get similar yes votes and cost at other regionals.
Do you really think the timing of the 15 airframes had nothing to do with the upcoming vote? JO knew he had those airframes coming long ago! He kept it in his pocket to get what he wanted.
United knew where those airframes were going long ago too. They allowed JO to keep that secret as leverage.
Even with the NO vote, the decision had long ago been made. They were coming no matter what!
Had Mesa voted yes, nothing would have changed with the 15 airframes other than other FFD airlines currently in negotiations would have been told "see, good things happen when you play ball."