At ~330 days out AA loads what’s basically a “rough draft” of a schedule. Roughly a calendar quarter out is when the replace this draft with an actual schedule. This is when people who already booked far in advance typically get a schedule change. If more flights are added then some are empty. Depending on the iming shift people might get offoaded from one flight to another and there’s an imbalance in some flights being relatively full vs empty. Sometimes this causes relatively cheap flights for new bookings (or it’s that revenue mgmt hasn’t had a chance to adjust things), and for those who’ve already booked if can mean AA is more cooperative when asking for different fights (in light on the schedule change).

I basically check for flights periodically to look for deals, usually on Sundays or sometimes mid-week. Eventually something good/decent usually turns up. I’ve got a recent post on another thread where I describe more details about how I search given the peculiarities of AA’s website (I’m not trying to be difficult—I’m on my phone and under someone’s flyertalk profile it’s possible to look at their list of past posts under their stats).