You'd also need to establish a much firmer, clearer connection between the leaders of the Rebellion and that redeemable element within the Republic otherwise the prequels ALSO have the unintentional side-effect of taking all the wind out of the Rebellion's sails.
Personally when I was watching the original trilogy before the prequels with all the talk of the Old Republic, a multi-species Rebellion (even though there's a grand total of TWO women in the whole galaxy but that's another issue), against a monolithic Galactic Empire it was
easy and made sense to root for the Rebels. They were obviously the underdogs and while no one was standing up and giving soliloquies on the rights of sentient beings or anything like that the story gave the strong sense that there was some kind of higher, justified reason for their struggle.
With how Lucas handled the fall of the Republic and the rise of Palpatine to his status as Emperor that whole sense of high-minded idealism gets a lot more hollow. When you've got things like Leia's adoptive (and never seen in OT) father as one of the major supporters of the war and the Clone Army, Luke and Leia's parents were both big-time war supporters, and no one saw the fall of the Republic coming until they voted Palpatine a crown its hard to make the "Good Republic vs Evil Empire" narrative stick when the people who are supposed to be the good guys aren't that much better than their enemies. It has the profound effect of making the Rebellion, post-prequels, feel less like some noble cause and more like a lot of sour grapes.
It doesn't help that the entire Jedi Council doesn't seem to have the brains or political instincts the Gods gave to insects, by the end of
Revenge of the Sith I was already thinking what was so great about the Jedi Order if they couldn't figure out the Chancellor who is quietly amassing dictatorial power is the Sith Lord they're looking for. The EU materials just make it worse by openly saying Palpatine had SITH ART installed IN HIS OFFICE!
The way Lucas was writing it you'd think the last frame in
Revenge of the Sith was going to be a propaganda video extolling the virtues of despotism
