AMR has every right to keep the airplanes. They will initially contract with AE for at least several years to keep flying them...otherwise nobody will buy.

A potential investor is essentially buying a feed contract and a seniority list. When the contract is up, the new owner can (and will) squeeze the pilot group for catastrophic concessions in order to remain competitive to rebid their own flying. If the pilots (and other labor) don't give up enough, some or all of the flying goes to low bidders.

And the investor doesn't even need that long of a guarantee...he's not investing massive capital in airplanes, just some light overhead and easily disposable labor. 3-5 years should be enough.