issue with the Big 10 or SEC poaching ACC schools is that ACC schools signed a CRAZY long grant of rights agreement that doesn't expire until 2036. This means that their media value to any new conference would be $0. So unless ACC teams hire very brilliant lawyers who can work miracles, it's going to be hard for ACC teams to go anywhere for awhile.
This gives the Big 12 the opportunity to solidify the central and western time zones. Great opportunity for the Big 12, especially if they can gain a toehold in California.