Even though Revan's story does continue in "KotOR II", I think his/her fate depends on the player themselves. I personally believe that Revan's story ended in "KotOR I", and the Exile's story began in "KotOR II". Since "Knights of the Old Republic II" was horribly written and unconvincing, I personally believe that it would be a horrible idea to continue with Revan and Exile. Since the developer of "KotOR II" didn't successfully execute a storyarch, I'm willing to bet that LA will just leave things be and move on.
Just my opinion.
Plus, Revan's and Exile's story is getting old and overexposed. If they continue with the storyarch, I can see myself getting tired very easy. A fresh story will be welcomed with new characters and planets.