As an aside two weeks ago I was upgrade from Y to C free of charge both ways on a cheap air miles earning ticket. Apparently according to various posts I recall reading to Bangkok there is a higher chance of being upgraded than other routes.

Flights was packed both ways and while I was originally not that fussed until my return flight CX702 went u/s and did not get away from BKK until 02 45 next morning after they substituted the inbound CX709 aircraft.

To add the CX crew and ground staff were magnificent in handling everything, especially people with connectons, though there was one American gentleman, who was definitely American but certainly no gentleman who was determined to make life as difficult as possible for people trying to assist and could not be blamed for the delay. He even gave the Qantas Club Lounge staff a hard time!

Suggest you check to see if you have been upgraded first if you have status on MPC go to the self check in as my upgrade showed up on the system there much to my surprise.