AA knows far more about the behaviour of passengers that we do.
They know who many no shows will likely happen and how many corporate bookings will likely shift to other flights in the days before a flight.
And never look at a seat map. it never reflects sales. many people don't select a seat until OLCI or physical check-in even if it is free of charge.
And if you get an upgrade then well done but if you sit in PE remember it's what you paid for.