I’ve thought about the sequel trilogy becoming more of an epilogue, but IMO it doesn’t justify itself well enough. The original characters in the sequel trilogy are (rightly) used to progress the new characters’ stories, and taken as a continuation of the original trilogy I don’t it serves to do what an epilogue should - to wrap up loose ends, to give closure. The only original trilogy character with new development is Luke, but his story in the absence of the main plot doesn’t really serve as a capper. Taken as an epilogue I think it would also undo some of the closure of the end of Return of the Jedi - a second Empire! Death Star 3! Another evil darkside guy! - it’s too samey so it undoes a lot of the progress made by the end of that film.

The best parts of the sequels were the new characters and their stories together - especially Rey and Kylo. The original trilogy characters’ stories in relation to our new mains were valid and valuable. The new threats - while almost exclusively old threats BUT MORE POWERFUL - at least gave our new characters good storylines in their own right, which goes most of the way towards justifying their existence (your mileage may vary).

In short, I think that the sequels have to be able to justify their own existence, otherwise why bother? I think the problem that we’re all mulling over on these forums lately is that TROS largely doesn’t justify existing, and it retroactively weakens the argument of the prior films by failing to deliver.