My cousin is at UAL in an affected BES... basically the staffing matrix is green so pilots can do whatever they want with their schedules and the company doesn't like it. QOL is too good for evergone in those fleets (756, 787, 777) in some bases so they're looking for a few (in some cases less than 3, in some cases upto a dozen) people to take a month off so they don't have to pay them to not fly.