So if I was her, I would have asked to get a written confirmation of this upgrade pledge from 'mgr Paulo'.
Seriously, what a drama for something that happened 20 years ago. Also, pretty typical "ma fan" locals attitude from Mrs. Chung of requesting something that goes way beyond 'returning the favor'. I mean, seriously, the entire family??? For some probably minor medical help offered?
Besides, if you know you wont be flying another CX flight in the next 20 years, then why not ask for something like a cash voucher or extra AM?
According to the story, the upgrade was offered to her entire family by CX 20 years via a phone call. No mention of her requesting this in the first place.
She was saving the "favor" for longhaul upgrade. She said her vacations were usually on regional flights. That's why she didn't request for it. So I am not sure if the 20 years without flying CX statement is correct.