If I have a flight from AAA to BBB to CCC, will I get the option to SDC to an earlier flight from AAA to BBB, even if it makes the connection time greater than 6 hours? Also what would happen to my pending pluspoints upgrade request? If there is open PZ on the earlier flight will I be upgraded? I also have to check in luggage, but I assume it won’t be a problem?

United changed the 777 last minute on my flight to one with much less lie flat seats 🙄 so trying to make sure I’ll get the upgrade.