This seems to be one of those rumors where everyone sourced it from one place. Every time I hear it, it has the same odd reference to Herbst trying to seal her legacy or set up some future gig and that's just not the way this works.
And it always ignores some pretty big logistics, like, you know, money. Going to the Big East would require a $10,000,000 check to the American, renegotiating all licensing and media deals downward, accepting a lower total payout from the BE vs the American and, ah, what do we do with our football program?
Unless someone tells me there's a magical provision that lets programs leave the American for free between television contracts, I think this one will run out of air just as quickly as it has in the past.