People are most likely going to be shuffled around to other planes. 737s use to be for a lot of short haul flights, but they're being used increasingly for mid

People are most likely going to be shuffled around to other planes. 737s use to be for a lot of short haul flights, but they're being used increasingly for mid and even long haul flights. They're often far enough it's impractical to drive, and at least in the European market, trains are always a more expensive, but available alternative. If the FAA took action, in the US people would probably just postpone trips unless they had the personal days to drive instead (or a lot of personal days to AmTrak instead). Most people will be shuffled onto larger flights to hubs with connections via smaller aircraft; so they'll be switching to airplanes with proven safety records. It increases demand for the seats and may raise cost, but safety would actually go up if it turns out there is a problem with the 737-max8.