My buddy was supposed to fly from ORD to ICT tonight but the flight got cancelled. The reason United gave to the pax was it was due to ATC. I dont really understand this. It was cancelled almost 4 hours before the scheduled departure time. Is there a more detailed explanation for the cancellation? Or is that just a made up excuse to cover up the real reason, for example, the plane not having enough pax to make it worth to fly the trip or something like that.