When you can check the status of the o/b aircraft, and you have a boarding pass with HBO, I'd not be going to the airport to sit-out a 2 hour delay.

Where things gets more uncertain is if you need to see a check in agent as sometimes they do close the desk.

The situation is also different at LGW/LHR as they can sub another aircraft at short notice and suddenly the delay disappears. At LGW, for example, they have a bit of a problem with crew not turning up for the longer sectors and falling back on stand-by.

If I had a message i would ABSOLUTELY trust it, particularly if I could verify the location of the aircraft.