I came
*this* close to a J to F upgrade on HKG-SYD last night.
I was paged in the The Wing and the agent asked if I would be willing to separate from the other three in my party to take the upgrade. I confirmed that "yes, I would" and she said "thanks, we'll call you in a few minutes". They never did - I double-checked my seat assignment at the gate before boarding and was definitely in J.