I really think a lot of negative energy is being spent over nothing. I'd forget about and move on. I say "nothing" because the OP doesn't have the facts. They are so many variables that caused the movement on the list and all that AA will do is repeat what those variables are (which some of the priorities are already posted on the gate monitor).

As an EXP, I see myself move regularly on the standby list, and just don't stress out over it. I know their systems will hopefully prioritize fairly based the established priorities, even if that means I may not be happy.

Time to worry about the next flight...