From what I gathered;

Trans states shut down mostly due to an inability to staff their flying and general mismanagement. They went to United and asked for some flexibility and United said no. That’s very different than United unilaterally pulling out of a contract.

Compass’ Delta flying contract expired and they were unable to secure enough flying to be a viable airline. Again, an expiration is much different than pulling out of a contract early.

That’s my take on it anyway. Let me know if I misunderstood something.