I don't think ESPN has the pull they use to have to form a seudo conference in the form of a TV deal. Texas would demand at least $25 million a year up front from ESPN to go independent in all sports, and they'd be crazy to do it.I agree that it seems unlikely, Texas would not want to have the west coast travel or be lost in the Pacific Time Zone ghetto; Pac12 would not be excited without Texas.
More likely is an ESPN grab, Texas to independent with a Notre Dame deal with ACC, Oklahoma + 1 (Kansas or Ok State or Texas Tech) to SEC, remainder of B12 left to fend for itself with the G5.