IE, have the new heroine be some unimportant person on some backwater planet having a meaningless adventure and remain completely overshadowed by the OT characters who did all the important stuff that mattered.
No. The OT heroes shouldn't have appeared in the first movie until the very end.
For example: a running plot point in the movie could have been Rey sending pleading messages to the Republic for help with a local matter that threatens her life (i.e., not "meaningless" to herself or the audience), and her community in general. She could have been a daring outlaw fighting against a corrupt system, barely surviving, and not knowing if her messages were even being heard. The climax could be a big ol' fight between herself the local baddie, where, despite all her courage and resilience, she gets beaten is about to be killed... until old-ass Luke and his pupils show up and save the day.
She'd tell Luke he was awesome for being a righteous Jedi Master, and he'd say, no,
she was the awesome one for holding out as long as she did by herself. And, for some bureaucratic
yadda yadda, the planet will now fall under Republic protection, so she can join his temple without feeling like she's abandoning her home.
Now that the audience is invested in her and has spent time with her, the OT heroes can take a prominent role in the second movie, while keeping to her general POV, without overshadowing her. They learn of a looming galactic threat with a connection to the baddies Rey was fighting all along, thus keeping her story relevant and prominent. Moreover, after a time jump of several years, she's become one of the temple's leading apprentices, and Luke himself is too beat up from decades of battles to be rushing into fights himself. Instead, he mostly provides backup and guidance from orbit.
And, as a shocking low point to the trilogy, at the end of the second film, Luke heroically sacrifices himself for his squad.
This approach:
- Introduces and foregrounds a new hero Disney can make money off of for years (maybe decades) to come, without being overshadowed by the OT heoes.
- Doesn't just rehash the OT, and doesn't trash the legacy of the OT heroes. Because the first movie isn't a rehash of ANH, the writer/director of the second movie doesn't feel compelled to toss all its setups, thus all but forcing the team to write the infamous words "Somehow, Palpatine returned."
- Keeps Luke from being an invincible, all-powerful superhero who can solve any problem, and keeps him mortal and vulnerable without betraying his heroic character.
- Gives the audience a few scenes of the main OT heroes interacting and working together one last time, while still keeping the main focus on the new characters.
See, it's not impossible. It's not even all that hard. It just requires a
bit more patience and forethought, and a willingness to risk a somewhat lesser initial box office in order to reap even greater rewards down the line.