Originally Posted by
RobertS975
All cancelling ahead of time does is help control IDBs. Those seats are NOT going out empty.
As we all know, the website will often not allow you to cancel a flight. And we certainly all know how difficult it can be to cancel by phone!
Whether you cancel ahead of time has absolutely zero impact on IDB. No one is going to be IDB'd until after the boarding deadline has passed, and the noshows who had confirmed seats have been dropped. So whether you cancel ahead of time, or cancel by no-showing, that seat will be filled before anyone is IDB'd.
Where cancelling ahead of time may have a
marginal impact is in VDB's where the flight is so oversold beforehand, that they're offering to confirm the changed itinerary/compensation without waiting to the end of boarding to confirm whether they actually need your seat or not. IME, when a flight is oversold to that point is when they're making those changes before ever going to the gate (in which case I'm not sure if it is even considered a VDB to DOT since it was resolved way in advance). But for VDB's that go to the gate, cancelling ahead of time probably has minimal, if any impact, for the same reason as IDB. Generally VDB at the gate doesn't finalize until they know they need your seat, and to know that boarding needs to have ended so the no shows can be dropped, and they still need to be oversold, at which point they will use their VDB volunteers..