I commute on AA every time I go to work, and yeah, they require you to "meal-list" now. AA changed their policy recently to not allowing anyone to just show up at the gate and list there. (Most gate agents will tell you they can't even do it anymore). You still have to check in at the gate once you get there, though, or they won't know you've actually shown up.
The number lowandslow posted works. They're usually pretty quick about it.