In my book they should have simply been allowed to go under. That would have negated all this discussion of what they can and can't do at this point.
I am not deciding anything for the courts. Been there, done that and the purpose of a contract is to protect both parties to an agreement from untoward consequences of unforeseen events.
Again, I am not defending them or making any attempt to assuage the deplorable way they did business. Just that with companies this big you are dealing with thousands and thousands of contracts and agreements that are legally enforceable. It's either meet the obligations, declare bankruptcy, or go to court as the defendant in a very expensive and time-consuming breach of contract action.