An option should be available on the airplane stand allowing you to divert individual or future flights to a different stand. This would allow you to rebuild a terminal or reroute baggage or anything else impacting the stand without canceling flights.
Currently if you want to change the baggage bay assignment you have to wait till the stand is not involved with a flight or other instances that require it to have no flights assigned to it. By temporarily or permanently diverting flights you can keep the terminal running smoothly.
Also this would mean if you have a large stand in an international zone allowing medium flights, you would have to reroute to another large stand in an international zone or whatever else is allow by the game to operate in the same conditions.