Is there any historical basis for how the traffic to cut is selected? Future flights? Existing flights? Short domestic flights vs international flights? It’s also unclear what the actual definition of ‘cut’ is
Yes, there's a well-established historical basis through Ground Delay Programs (GDP). The FAA uses "Ration-by-Schedule" delays are allocated based on your scheduled arrival time with adjustments for airline equity. Flight selection: It affects flights already in the system (filed flight plans), not future bookings. The scope is defined geographically all flights within X miles or specific air traffic control centers…
Of course the deep state would have a well-crafted and equitable contingency plan.