https://www.cougarboard.com/board/message.html?id=26611869
This was written before the Big 12 finalized invites for BYU, Houston, Cincy, UCFz but you can definitely see the similarities.
I think the one spot that the Big 12 has the advantage is that they didn't lose any other schools after the big defections. The Big East list TCU and WVU and that ultimately doomed them. If the Big 12 had lost WVU and Kansas (or similar) they'd be in the same path.
That said, the next TV contract is going to be a huge deal. Every major change is seemingly spurred by TV deals