Originally Posted by
jantaoYVR
The option only shows if there is positive space on the flights you're looking to SDC to. If a given flight as a whole is oversold by even 1, the option to SDC to that flight will not show (remembering the caveat that only the next two available flights will be presented).
Given the long weekend, I would suspect that the flight you're attempting to change to is oversold.
I just called the concierge and she is looking into it. Will call back.
Menwhile the first flight appears to have been switched to a 319/320 from an E90. With lots of seats presumably. Which may not have been the case last night...