Gotta be a staffing issue that is working out in your favor. Take advantage of it while you can for sure. I will say it isn't considered "normal" by any stretch at the new United to be able to drop trips (it really wasn't at the old United once unimatic tt went away)

Once normalized, that "perk" will go away. Therein lies the problem. The company controls not only the staffing and reserve coverage but also all parameters of the trip trade system. They hold the cards. I have only had luck trading same day, same number of days and an earlier departure.

Scott