GF
OK I'm no Airline Route Procurement Executive (In my dreams perhaps) : but some basic "Duty of Care - Due Diligence " sort of procedural processes would have been applied here by both sides, as a mutual protective activity, by contract, and established by mutual agreement to protect both parties. and third party customers
I'm not really qualified to express a direct opinion in this case, but surly - as part of the established "Economic validation criteria of a potential customer " the "provider" and "customer" would mutually agree on an "established pattern of service" for an agreed period, subject to agreed unforeseen circumstances.
What went wrong: Better informed contributors than I have raised pertinent questions in this respect.
CAT III