Seems to me IF the B1G Conference really is serious about expanding some more, they'd just go ahead and add the teams they want now but to become effective right after the conference media rights of the joining schools expire. That's a pre-emptive move to make sure the media rights thing doesn't forever stand in the way. Then the B1G would just negotiate its media deal to expire or be revisited at the same time the new schools actually join. This would certainly work well for Oklahoma, Texas and/or Kansas. But the expansion deal announcement coming years before the effective date probably would actually trigger or pull ahead the destruction of the Big 12 and/or the ACC a lot sooner. And thus the expansion would end up happening earlier than originally announced. I think it's a strategy the B1G could use to get whatever teams it wanted assuming it still wants to expand further.
