They're called "DLC" (only because they were "Downloadable content" in the console versions of TFU, before the Ultimate Sith Edition) but they're there from the beginning.
I suppose there isn't really a big problem being separated from the main campaign (and it gives people who have already gotten bored with the main game the option to go right into them). But I heard one of the missions should actually take place in the midst of the main game, is that true?
It would be neat to know which space that is. Do you have to re-earn any force powers that would otherwise ruin the illusion that it was one giant continuous campaign?
Btw, can you have multiple saved games in this one?