Unlikely yes. But never say never when lawyers and large sums of money are involved.
I just threw those names out there as possibles. AAU membership is almost a certain, if unwritten, requirement for B1G membership.
Non-B1G AAU membership (BCS members):
Duke
Georgia Tech
Iowa State
Rice
Texas A&M
Tulane
University of Arizona
University of Buffalo
University of California
University of California, Los Angeles
University of Colorado
University of Florida
University of Kansas
University of Missouri
University of North Carolina
University of Oregon
University of Pittsburgh
University of Southern California
University of Texas
University of Virginia
University of Washington
Vanderbilt University
Better than even chance any B1G expansion comes from that list (ND excepted). Throw out the PAC 12 and SEC schools. I do not see anybody leaving the SEC for the B1G, not even Vandy.
Only three schools on that list come with no strings attached, Buffalo, Rice, and Tulane. Only one of those are in the B1G geographic footprint, Buffalo. Sorry, the B1G and Buffalo do not fit together, not even with AAU membership.
And unless the B1G just wants a presence in Louisiana and Texas, I do not see Rice and Tulane being viable choices either. Their chances are only somewhat less than the proverbial snowball....
So unless one is willing to say, and I am not, that Buffalo, Rice, and Tulane are legitmate contenders for B1G membership, all that are left are schools with lots of legal issues (in terms of changing conferences). Thus, enter the lawyers and money. Freedom can always be had for a price.