They are not in a situation financially to leave the Pac12. There's very few outcomes that aren't disastrous for the athletics program.

Scenario 1 (Very unlikely) - Pac12 invites MWC teams and somehow manages to stay afloat. I don't know what MWC teams would take that kind of gamble though. Its a sinking ship and at this point the Pac12 is basically handing those MWC teams buckets and begging the existing teams to get off the lifeboats.

Scenario 2 (Unlikely) - They get an invite to the Big12. I want this to happen like I wanted a new truck for Christmas. You know, the kind you see in commercials around November with the model wife walking you out the front door of your perfectly shoveled driveway to see the pristine F350 with a matching red bow on it. We live in reality though. The truck didn't happen, the bow didn't happen, the shoveled driveway this winter didn't even happen.. and no, Wazzu in the Big12 wont happen either. My wife is also reading this over my shoulder.. the model wife thing did happen.

Scenario 3a (Extremely unlikely) - Somehow Washington state passes legislation making it so both WA and Wazzu a package deal. ACC, SEC or B1G accept it and figure they can't be worse than Louisville, Duke, Indiana, or Vandy.. right?
Scenario 3b (Extremely unlikely) - Somehow Washington state passes legislation making it so both WA and Wazzu a package deal. ACC, SEC, and B1G all collectively say "nah", and WA goes to another P5 leaving Wazzu to independency.

Scenario 4 (Likely) - MWC. They wont make enough to stay afloat and I see them only lasting 5 or so years. I think this is the best-case scenario as it at least gives them a chance to let the dust settle and for the inevitable collapse of the current conference setup to happen. College football splits into 2 semi-pro conferences and one of them will pick up Wazzu out of the need to fill spots.