Yesterday I flew CX685 from HKG-BOM, ticketed in Y. Checked in at Airport Express Hong Kong, and the agent asked me if I had done a mileage upgrade. I said no, probably because I'm a Gold member I got an upgrade. She asked to see my Gold card () and then gave me a J class BP.

That means I was op-up 2 classes from Y to J, bypassing Y+.

The strange thing was that Y had a few empty seats and Y+ was half empty. So why was I op-up to J? I still have no idea!!

This particular flight took me over 500K Club miles, but I understand the milestone upgrades happen after the milestone happens, not before. Also they would tell you why you have been upgraded in that case. Here nobody said anything.

My boarding pass had no letter on it "I" or "V" indicating involuntary or voluntary upgrade.

Any ideas?