I don’t think that it said that they will definitely all be gone. The 50 seaters sound like they are not going to be part of post recovery United regardless, but the United fleet depends on the speed of the recovery. From what I read, if the recovery is slow, the 756 would be the first to go, followed by the older Airbus if demand stayed depressed. Basically, if things stay really bad, aircraft will go, if not, then they will adjust to the anticipated demand at the time.