isn't taking them now, that's fine. I haven't got a problem in the WORLD with treating UW and UO like a trade-deadline acquisition. A rental in order to kill the Pac, but do it in such a way that you're not taking the dregs (okay, two schools up from the dregs) of the Pac to do it.
Offer a day-one full share plus maybe a sweetener for the longest travel, and put a very modest exit fee in their contract IF they are invited to the B1G specifically.
Then, besides them, you take the best two Pac schools after that to kill the conference all the way dead.
So for UW and UO: more money now and an easier path to the B1G in the future (than the big GOR the rest of the Pac would insist they sign for staying), and if that call never comes, they're not saddled to a dying product and anchoring a conference that'll have to backfill with MWC teams.
And for the Big12 : the best two teams from the Pac now along with two middle-of-the-road Pac-ers, rather than 4 middle-of-the-road Pac-ers to begin with. If UW and UO get the call-up, ah well, have the option to backfill with the best two former Pac-ers at that point, or potentially, the option to backfill instead with more appetizing ACC schools.
Win-win...win...win-win-win.