That is the argument I heard from a national writer. I think it was Dan Wolken.
I tend to think of it this way BYU is already on the ESPN payroll. If BYU is added to the BIG 12 they will be able to take BYUs contract off the payroll and in a manner get a discount on the pro rata agreement with the BIG 12.
If any other team is added ESPN will be paying full price for the pro rata clause and in some cases more paying more because they will have to continue paying the conference where that team came from and the pro rata clause.
Is my thinking correct?