Originally Posted by bdemaria

Person #5 - who cleared - was likely waitlisted to upgrade from J to F. The app doesn't differentiate between J and F upgrades.

As for your position on the waitlist, it does shift a lot. Upgrade requests are based on the time of original request. When you checked in - and were told you were #2 - , this means that only one person who requested an upgrade who had priority over you (either via an earlier request or higher status) had checked in prior to you. Since that time, other people who requested their upgrade prior to you and/or have higher status than you - have checked in - and retained their place on the upgrade list.