I've long since learned to think of production seasons and broadcast seasons as two different things, especially where animation is concerned. FOX dragged out Batman: The Animated Series
's two distinct production seasons over something like five broadcast seasons -- 55 episodes of season 1 the first years, the last 10 episodes of season 1 the next year, then season 2 broken up into 5, 10, and 5 episodes in the next three years, with the rest just being reruns. So Futurama
's case was hardly unique. And it's common these days for cable series to have production seasons that are split into summer and winter broadcast seasons, or even to be split across two consecutive years as with Eureka
once or twice. And even when they're technically half-seasons split between summer and winter, they still get touted as "seasons" rather than half-seasons, or at best as "summer season" and "winter season."