It's because this game has lost SO MANY players they haven't sold anywhere near the amount of DLC/Season passes as were expected. The DLC sales numbers have went down considerably since the first one and the season pass wasn't as popular due to people being skiddish after the last few fiascos with them
I can understand how that must be frustrating for you with the two week later aspect. I bought the season pass early, so it doesn't bother me that much. I feel if this strategy works for IW, and it gets ppl buying the map packs & improves this fiasco with Lag & finding games while partied up that I have been experiencing for the last month. I'm all for it!
Now I'm not sure this is the reason for the lag as of late.... But good grief I'm in to try any angle to get a fair game.