hi, I'm new in here.
I'm just curious about CX upgrade class
its happen on my holiday last year on july
my ticket for outbound flight is premium eco W/R class If I'm not wrong
my ticket for inbound flight is business
my flight are SUB-HKG, HKG-SFO
on first leg I'm sit in economy because SUB-HKG doesn't have Premium eco class
on 2nd leg while I'm queuing to aboard the plane suddenly my ticket upgraded to business class without any miles (me and my brother ticket)
on my flight home I'm sitting in business class so i don't think need any upgrade but my 3/4 friend upgrade at check in counter from eco to premium eco without any miles.
my question is, on that moment am i and my friend are lucky or thats possible upgrade without any miles?