A new Return of the Jedi. basically the same movie but with some different exposition. In the past, the “real” Darth Vader kidnaps and has his wicked way with Mrs. Skywalker. Anakin has to free her but is killed. Obi-Wan of course wouldn’t know that Anakin is not the daddy.
So in ROTJ we have Darth Daddy rather than Obi-Wan The Liar. Leia wouldn’t even be a sibling to Luke. Maybe she is the real progeny of Anakin Skywalker. Or maybe she’s just Bail Organa’s biological daughter. Leia hates Luke because he reveals he is the son of Vader (instead of her brother) but at the end she knows the hate is misguided. But she’s already got with Han, which leaves room for romantic questioning in the future.
So we shall put this fantasy into an idea where Luke has a more ambiguous flirtation with the dark side. Sequels continued coming out every three years 1986 1989 etc. There is no OT but an ongoing triennial series of movies in various episode order so as to foment maximum anticipation. The prequels would end up being more in line with all the hints we hear from Ben and Yoda. Anakin was a cool dude, and Obi-Wan’s friend, but is not Darth Vader or Luke’s dad.