For the B-12 this is entirely about positioning for the future, if it requires some redundancy (two schools in the same states, Ut & Az) so be it.
The P-12 is either going to die a slow death or it will reinvent itself. If it reinvents itself, that will primarily be at the expense of the B-12, which is what the B-12 does not want to happen. Oregon and Washington are going to bide their time until the B1G is ready to add a few more schools. Cal and Stanford are going to hope they can remain at income and competition levels similar to what the current P-12 offers long enough to still be somewhat attractive if and when the B1G finishes adding schools (10-15 years out). I personally still see a reasonable chance that the SEC (when they decide to expand past 20, also 10-15 years out) will look seriously at Arizona & Arizona St.
I've felt all along that our best path at a B-12 offer would be if Colorado accepts and all other four corner P-12 schools decline. I also believe that the only chance we will have is if an odd number (one or three) of P-12 four corner schools say yes. If the B-12 can take any P-12 members this will be a blow to the P-12. If they take three or four, this may cripple the P-12 as if nothing else, it will allow the B1G to move more quickly on Washington and Oregon without fear of litigation or being labelled a conference killer.
I also will repeat (mentioned a few times in earlier posts) that nothing will happen until the P-12 finalizes their new contract terms. Nobody is leaving the P-12 prior to fully understanding what it is they are leaving. This doesn't mean that we will hear the P-12 contract announcement first, merely that all schools will be presented with the terms and and schools that may consider leaving will decide at that point.