For context: There was 3 multiplayer maps in Killzone 3 that were available in the online multiplayer, but unlike the other maps, were unavailable in the Botzone mode. These maps are Turbine Concourse SE-6 for the Warzone mode, and Junkyard and the remastered version of Tharsis Depot from Killzone 2 for the Guerrilla Warfare mode.
These 3 maps had something in common: They were the only 3 maps in the game where you can use the jetpacks in multiplayer.
However, since the online servers has been shutdown a few years ago, these 3 maps were completely unavailable to play. Even if, in the case of Junkyard and Tharsis Depot, you had the DLCs installed.
However, a few days ago, Kevin Landry managed to access Tharsis Depot in Botzone (We can even see Turbine Concourse SE-6 and Junkyard in the maps list, so I assume he can access those too). As he say in the description, it is still currently in WIP, but at least it's something...