Revan returned from locating the Ultimate Evil, and was still alive?
(Time-space warp and was only gone for 5 years to him, and has his entire fleet still? [0 bby])
I think that was the end of Forces of Corruption
If he did I am sure he would encounter the Empire and the Palptine might have either made a deal with him, destroy him, or somehow trick him.
If he ended up encountering the Rebels first I think the rebels would be basicly destroyed. Eventhough Revan's fleet is out dated by now they still have a force user and a good amount of Sith soldgers. (This is all concidering the lack of numbers for both sides and that if they engaged rebels it would have to be on Yavin, Kashike, or possibly over tatoine right before the Imperials arrived).
If it was the third event I think the rebels would escape useing Revan's fleet as a distraction for Vader and his fleet to deal with and the events after that I am not sure but Alderan would still be destroyed or under threat of being destroyed to trade for the plans.
(By the way I am aware my spelling sucks)
What would have happened if somehow the rebels found an army of clones from the clone wars that betrayed the Emperor for some unknown reason??? (This could be at any date from the formation of the rebelion to the times after the battle of Endor)
Joe