Does this suit have any merit at all? Diclaimer: I'm not a lawyer.
The period of benefits have never run the calendar year (used to be March 1 to Feb. 28, then Feb. 1 to Jan 31).
I'm assuming the "contract" breached was based on the benefits promised. However, aren't the terms and conditions of the program part of the program? These state UA can change the program at any time, and change benefits of the elite program, I'm pretty certain.
Yes, perhaps it was not nice of United to announce mid-year that the benefits of the following year would change. Customer-friendly? Certianly not. Illegal/breach of contract. Seems highly unlikely to me.