A gate change is an announcement that your departure door has moved. A late gate change, watch for a gate change.
It is the commonest reason people miss a flight they were already at the airport for. Screens update before announcements do, which is why the screens are worth watching.
1noungate changeAn announcement that your departure door has moved.
“A gate change sent the whole queue back through the terminal.”
gate change is an announcement.
Practised in Airport & Flying