You’re right about Linux but you’re wrong about windows. It is sent to the event loop in windows https://learn.microsoft.com/en-us/windows/win32/winmsg/window-notifications. It’s been a long time since it was my job, but you actually had to pass a certification that your application exited gracefully in response to these messages as part of the partner program back in the day.

People having seen the exact same joke that isn’t even good for a decade or more…

I’ve never liked this joke. I guess it’s supposed to be that the husband does the literal action as described, but instead it’s just that they interpreted ambiguity opposite than expected? It just really doesn’t work very well :/