Yeah, that doesn’t work still. Her parents being nobody was about her not feeling like a part of this big and important conflict. Her grandfather being the biggest and most important part of this almost-century of conflict does contradict that. It contradicts her emotional arc of having to create self-worth, rather than her importance being externally from who her parents and grandparents were.
Her feelings of worthlessness don’t come across at all in Rise of Skywalker. It’s a feeling that she must be evil because Palpatine is evil. And overcoming that is literally what Luke already went through with Vader. It’s reductive to Rey as a character on a storytelling level, repositioning her again as a proxy for Luke rather than an autonomous character, and it’s also reductive to her arc that she already went through in Last Jedi to learn that she is her own person regardless of who her family was.
It’s just bad writing. Like it all you want, maybe it helps you with the accusations that she was a “Mary Sue” or whatever. It doesn’t make up for the fact that it was bad writing that hurt the character and story. Maybe that can and will be fixed, but it hasn’t been yet.
A grandfather who wants her dead. And then a grandfather who wants her to attack him so he can take over her body. Just all sorts of good feelings there. No, the story is really about Rey’s self worth. She starts with depending on her family coming back for her. When she is shown that is never going to happen, she transfers that to the OT heroes. But Han dies and Luke won’t leave Ach-to. Kylo tries to convince her that she has no place in the story. But Leia makes a place for her. When we start TROS, Leia becomes her teacher. And she still thinks she is unworthy. She finds out she is a Palpatine and she feels even less worthy. She is now the enemy. She tries to hide, but Luke sets her straight. Then when she calls on the Jedi in her greatest need, they are there. They support her. The show she is worthy. Not because of whose family she came from, but because of who she is as her own person. She defeats Palpatine because she casts aside preconceived notions, which she and the audience have had since the story started, and comes into herself. She is Rey. She takes the name Skywalker to show that she rejects her Palpatine lineage. So every piece of her story builds on what has come before and TROS doesn’t retcon anything. In the end she has found herself and her purpose. And it was not based on who her parents or grandparents were.