Kreia: "You must go where Revan did, into the Unknown Regions, where the Sith, the true Sith, wait in the dark for the great war that comes. And he came because Malachor, like Korriban, lies on the fringes of the ancient Sith Empire, where the true Sith wait for us, in the dark."
She actually states it in the game.
Hmmm, never heard Kreia say that in the game. Must have missed something.