I think that Revan found a secret, hell to know what it would be, the "True" Sith could be the Vong, because Canderous mentions seeing their little scout ship in KotOR 1, they could have set up colonies in the Unknown Regions or it could be the Sith, and they have set up a hidden Empire. What I think is going to happen, is that the Jedi Order has been rebuilt because of the "True" Jedi, Atton, Bao-Dur, Bastilla, Brianna and Visas and they have begun training other Jedi Knights. Then Revan and the Exile at least make an appearence or they are in the game and tell about a Sith attack from the Outer-Rim. And again you have to stop them from destroying the Galaxy.