A note about the timing of "when" AAA rates are released .... once WDW releases their yearly rates, then within a week or two AAA releases their discounts.
So usually, WDW announces their next year pricing in July; thus, AAA discounts will be available shortly afterwards.
Remember that, just like other discount codes, they only have so many per resort/time period. If you are going during a busy period, you may want to book early to obtain the AAA discounts because they are limited.