It turns out no matter how the soon-to-be-former members of the Pac-12 realigned, they were going to do so without Oregon State and Washington State.
Brett McMurphy of Action Network reported one Pac-12 president contacted a Big 12 counterpart and asked if the league "could take all of us, except for Oregon State and Washington State."
It's unclear what the answer to that question was, but the plan did not come to fruition. Oregon and Washington wound up committing to join the Big Ten, while Arizona, Arizona State and Utah joined Colorado in leaving for the Big 12.