The DLC maps will arrive later on, the Free Fall one was a pre-oder one on "old" gen consoles but is now part of the season pass, I'm not sure how that works, but if you didn't pre-order in an old console you might not have the Free Fall map, however, if you purchased the season pass recently, try updating your game, the map does not install within the season pass itself.
It is as maccabi and Ozhm said, the 4 DLC maps have not yet been released. Apologies for the confusion, but yes you do get Free Fall map as a bonus with the Season Pass via ONSLAUGHT, DEVASTATION, INVASION AND NEMESIS Bring Call of Duty®: Ghosts Content All Year Long. As far as the Free Fall goes, you should be able to download it by following the steps listed here via Activision Support. You can also push the download from here Digital Entertainment | Sony Entertainment Network.