based on how the first two games were designed, the main character would have to have gone through some event that would caused him/her to lose his/her memory. or at least the character should know just as much about what is going on as the player. it wouldn't make sense that we would have to play as either the exile or revan again unless the corny idea of revan losing his memory by the jedi council is used again.
"Do what must be done, do not hasitate, show no mercy!" ~ Darth Sidious
"Peace is a lie, there is only passion.
Through passion I gain strength.
Through strength I gain power.
Through power I gain victory.
Through victory, my chains are broken.
The Force shall free me." ~ Sith Code