Are they though? A random reporter said that, and made a guess at which schools. I would guess Colorado would be one, Colorado would still be a boundary school and an AAU school, so that is a PAC12 school they could be reaching out to that fits their bylaws.
And then if CO joins that means Utah and AZ also fit with the AAU and contiguous border schools. So they could easily be reaching out to those.
That being said who knows if any of them jump to the B1G or if more than 1 do, we still could fit in both conferences at this point.