*IF* that's the case then it make sense why the ACC acted now. If the Texases and Oklahomas go west, then of course the B12 is dead. And the SEC and Big 10 might get moving to 16 themselves to keep up with the Pacific Joneses. The ACC is simply going to lose if teams on the open market (meaning remaining B12, Big East and major leftovers) have access to all 3.
Makes me think the ACC learned from the 2003 debacle. Back then Duke and UNC were principled votes against expansion, and it was that which made VaTech getting in possible (and keeping out SU). I think they realize now that if expansion is inevitable better to lock in your preferred schools, in terms of academic, cultural and geographic fit.