I haven't played the SP campaign (just the demo and the very first mission) and I don't plan to play it through until after I've seen ROTS.
However, from what I've heard, the "Hangar" map shown in those trailers is not present in the retail game.
So apparently it was axed before release. We can only hope that perhaps, like the Azloc III Base map for Jedi Outcast (which was an expanded version of the JK2 demo map first shown at E3) this map will be finished up and released as part of a patch, expansion pack or something.
Could it be unlockable as an easter egg? Doubtful, as you'd think somebody would have found it by now, since the game is so short and relatively easy to beat.