That's the point, in no way a main character can become a supporting character in the same saga without splitting it in two. And this happens several times, among many other inconsistences. What's more, the used past of the OT now (if you watch the saga in order) looks almost unbelievable... "How's that... no one remembers Yoda (I accept no one knew he was alive), even if the Rebellion seems to be so related to the Jedi? No one asks Luke "hey, are you the son of the great Gral Skywalker??"... No one knows Vader is Anakin?.

Even though I think it'd be cool that some of the adjustments which need to be done to fix this should be actually done in the OT (like making some rebel team mate ask Luke about Anakin, as I said before... because,umh, well, I think it'd add to the spirit of ESB), I hope to see what can be done in the prequels to make them suit the OT universe