Originally Posted by
JacksonFlyer
I noted in one post days or weeks ago, someone with status who had saver was able to move up to without having to pay extra due to lack of passengers on the aircraft.
While op-ups are nice, that's an outlier situation that doesn't really count as "upgrades from Saver." If that poster hadn't been on the plane, it'd just have gone to a Y passenger without status, and theoretical upgrades when weight and balance need to be tweaked aren't an advertised benefit of flying any airline.