I think a brilliant way to open Episode IX would be to pan down from the stars, and pull us down onto the planet on which Luke's old Jedi Academy stood. But this time in all it's bright, shiny glory, with young students filled about and Luke, Han and Leia having a good conversation about life (Leia's dialogue would of course have had to be shorter due to her untimely death), past and future. This way we could open with the original three - seeing them having their good days between RotJ and (pre-)TFA, before moving onto the end; making us all feel a little fuzzy and warm, once more, before the bitter end.
It would also serve as a nice mirror to Palpatine's now confirmed return, having Luke and friends open the movie - only for The Emperor to once more cloud the world that Luke helpt build (before Rey whacks up Kylo/Emperor evil plan of course).
I really don't see them doing this, but man would it be a great testimony to the love and passion these three characters brought to the world of Star Wars.