Usually you have to scan your boarding pass at least twice at the airport: First at the security checkpoint and then at the gate for boarding (plus once more if you check bags). If somebody does not check in bags, does the airline know that a passenger arrived at the airport and at least made it to (not necessarily through) security? If so, would that be a trigger to call somebody out before the flight closes (and also to not call out if that passenger hasn’t even scanned his boarding pass yet at security)?
(Moved here from aviation SE)