reply by MPC
Sorry it took so long...
The end of story was that the MPC sent me an upgrade certificate and apologized... NOT for not upgrading me BUT for not letting ANYONE know that it was my birthday.
Cathay Boy and others... I mostly sleep on long-haul flights and I fly J so it's not the UG that mattered but the fact that CX would not bother informing the crew.
Honestly, I DO NOT want anyone singing happy birthday to me at 11km above sea level :-) It was a glitch, it happens, end of story.
Paradoxically the same day I was told by MPC about the upgrade certificate I flew back to HKG and... I got upgraded (flight full).
I think CX's real strength is the inflight crew. Just give them the info they need. They know how to make passengers feel "special" and it costs nothing to the airline.
Happy flying