For me the key term is in some form. That doesn't indicate a wholesale absorption or even the Big XII shell being the shell used for the "merger". I still highly doubt that the AAV for an 16 or 18 team Big XII is greater than the AAV for a 14 team Pac-12 that included Tex. Tech, Ok. State, KU and Houston. Now if the Pac-12 loses Oregon/Washington or more then it becomes more interesting as at that point the Arizona, Colorado, Utah combo are the most valuable assets in that league shell. The best case scenario for both leagues would be a 12 team league that took the Pac-14 scenario and dumped Oregon State and Washington State.
If not for the addition of the four AAC schools, I think the Big XII would be in a much stronger position, as some of this is, in part, being driven by a lack of confidence in the Pac-12 leadership among the member institutions.
Worth noting there is some reporting that no Big XII meeting is happening:
Source:
Canzano: Oregon Ducks make a wish list, while Pac-12 rallies behind scenes