They are not trained in priorities, because, as per BA policy, no staff passengers should be onloaded at the gate.
What a complete load of twaddle.
If there are spaces available and the full checked in load shows a minimum of 10% free space then check-in will issue you with boarding cards with seats prinited on them.
The ONLY reason you would get through to the gate without a designated seat is if you agreed on a tight flight that you would take your chances at the gate. The only station which does not allow blank cards to the gate is LHR T5, that is not a function of BA but a function of the DfT who won't allow passengers without allocated seating through security. Don't believe me then have a look at how many staff are at the gate in LGW for a popular commuter flight.
If the Captain then decides to release jump seats at this point or there is a late no show then you will get your seat. That can only be completed once the flight has been closed and it can be confirmed that no more commercial passengers are coming. The reason it take until the last minute is that the dispatcher must reconcile the seats available and confirm with the Captain if the jump seats are being released. This only happens on a full flight with overbooking. I've been through Malaga several times in the past on ST and never had a problem except when the flight has been way overbooked. Then I've progressed through to the gate with a blank card to get the cockpit J/S if needed.
There is no 'ba rule or policy' it is merely governed by the standard ST regs and local station regulation. Neither would ST passengers be left behind due excess cabin baggage. The gate staff have no authority to issue seat allocation at the desk, they need the authority of the dispatcher for that, who is, usually, quite busy.
Thread creep over.
