Twas a joke. The problem with a season pass is that it schedules them for a certain amount of DLC. The problem with being scheduled for work on a certain amount of DLC is that once they are done with working on that DLC that they are committed to work on they are off to do something else.
Gears of War 3 season pass gave you 4 DLC packs. At the end of it they said if the demand was there another DLC could come out. The demand was there. They moved on to make Gears of War: Judgement.