I don't advocate Christmas Day working. I do think some services should be available on Boxing Day.
I would hope it could be staffed by volunteers, but if not then perhaps the contracts need to be reviewed.
I would have been content to work (some) Christmas Days.
I did work one Boxing Day. (Some scrotes burnt down a key piece of signalling infrastructure on Christmas Day; we went in to put together the emergency timetable.)
Why review our contracts? This is what I don't understand.