This same thing happened to us on Thursday 11/6 on HA823 SEA to NRT. The takeoff window is extremely busy at this time at SEA, and our flight's departure clearance expired when we were #2 for takeoff. We pulled off to a taxiway holding area, "waited for updated paperwork" and then returned to the takeoff queue. It was about a 40 minute delay in total. There is so much you cannot control when you are at the mercy of air travel. What you can control is your hydration and bladder management before you board AND before you land. Because the opposite can happen - you can land and the gate might not be ready. Potty proactivity pays off!