Originally Posted by
skimthetrees
Yes, Y or B Class economy upgrades to Business when using United miles for SAUA.
As I read it you do not have a free 24 hour cancellation period. What you probably will have, based on my check of the EVA B fare on their website, is no change fees with a B fare (any fare difference and tax difference are charged) so you can easily change to a different date for free (fare & tax difference) if SAUA is not available on the original date you book. I would still call to check for Z before you book.
I just called and there were 2 spots in Z, so I bought the ticket and was able to immediately upgrade. I can't believe how easy that was. Thanks again!