I don't know the answer. This is actually the first time I've heard that they force people to miss a flight. I've always assumed it was just that they pay up to a certain amount for people to give their seat up and then give up trying, and have flight attendant extras all over the place and can go 1 short on flights or 1 extra as needed according to algorhythms. Sort of how U-Haul works with trucks and trailers so you can take them anywhere and leave them there.