This happens with UAE fairly often, east coast legs, IAD CHO, IAD PHL, usually the late flight, it is pretty apparent when the plane is there, the weather is fine, there is no mechanical problem and there are two of you in the boarding area. It happens so often, I always have a car booked prior. but, as a 1K at least UA DOES put one up in a hotel, or sometimes puts the few of us in a cab.