Based on difficulty to get ressies, it appears that one of the hardest times, if not the hardest time, to get is the first two weeks of December; holidays like Christmas, Easter (and to a lesser degree other spring break weeks), Thanksgiving, and Presidents Week, are also difficult; Summer other than July 4 week tends to be fairly easy to get and even July 4 can be had 6 months out; September and January are usually easy; and other times can be busy particularly if there is some event (e.g., wine festival). So the answer is generally no, it does not follow the typical season breakdown. It tends instead to follow what you might see from savvy owners, who are repeat customers to WDW: when they must live by school break times, holidays are biggies with the heat of summer being a choice but more avoided. When they don't have to live by school break times, they go for lower point times and particularly those that offer special events with the biggie being Christmas decorations and events in early December.