You could tell the story of the events after ROTJ and make it stand on its own. You could even improve upon the originals (a difficult task, but not an impossible one). This movie did introduce some new and potentially interesting themes: out with the old and in with the new, the Force is out there for everybody and not just the gifted, animal cruelty is bad. But goddammit make up your own story to convey those themes.
I think this is the point though. It’s one of the main themes of the movie, expectation of legend vs our own humanity. The expectation that Luke is the infallible hero and legend who will step up to fight the First Order, Poe’s assumption that being simply brave and courageous alone is heroic, the expectation that Ben can still turn back to the light, that Finn and Rose’s adventure will make a difference on good intentions alone, or that Rey is a somebody…
I think parroting sequences to subvert them is how Johnson is presenting that theme that the legends and stories we (or the characters in this movie) try to live up to aren’t plausible. TLJ more than other SW movies tries to speak to our humanity and fallibility. Ben won’t turn back to the light side, Poe isn’t really a hero, Rey is a nobody, and Luke at his core is just a man. It turns around to paint the OT as an idealistic fairy tale, and that’s what’s so different about it thematically.
I think that theme becomes muddled if you don’t have the familiar story beats set up to subvert later. Otherwise you rely on even more obvious telegraphing or expositing of the theme like some lesson at the end of a school special. Rose discovering her “Resistance hero” attempting to escape at the beginning would be an example.
Not with Rey though. Her only flaw is being a nobody and that’s not a flaw at all. Maybe you could make a case for her being an idealist but she’s never even punished or suffers for any of her choices, and that’s not necessarily a flaw either. Her character is still almost the same character she was at the beginning of TFA, except that now she’s a lot more powerful, without any real explanation as to how. One of the few differences between TLJ Rey and TFA Rey is that she cares about the cause and about 2 or 3 people, but that’s it. I just can’t see Rey as a compelling character.