Ah, that makes sense. I’m in the military, and we have a similar thing for people who are either due to transfer or retire in the next couple months: FIIGMO. It means “Fuck it, I’ve got my orders.” (For clarification, orders in this context are travel/Primary Change of Station/Retirement Orders, a written and signed document saying they’ll be leaving)
It seems like a weirdly deliberate term for something that has been around forever and typically just attributed to low morale. It makes it seem like a person unhappy at work but just doing their job is somehow sticking it to their boss/company. I’ve dealt with a lot of people like that, both as a peer and a supervisor, and it was never them doing anything intentionally, just being unhappy (and most of the time it had nothing to do with the pay or conditions, just not being suited to the job or general attitude toward life). They could often be a blight on morale, though, so I see how it could be frustrating for supervisors (and peers, they made work miserable for everyone).