Imagine how much impactful if it were revealed that all along, Rey was indeed a nobody. Hm, but we already understood this in TLJ, you say. Yes, but in a ‘shocking twist’, it turns out Rey felt that “awakening” of the Force, reverberating from Luke like a unconscious cry for help. Faint, but strong enough for the isolated Rey on Jakku to have some unknown divine energy compel her on a journey. Luke didn’t really intend to call-out to anyone nor expect anyone to answer his SOS. But yet the Force weaved together a string of interactions. Destiny.
Rey comes to a new understanding. She doesn’t need to come from some royal bloodline. Her parents didn’t need to be big names in the galaxy. She herself can be something from nothing. All her psychological misgivings from earlier was a reaction to not believing she had any value due to how she grew up and the story/myths surrounding the epic tales of the past.
Palpatine simply having any familiar ties sounds like something brought out of left field. If it was perhaps hinted at here and there in any of the past two films, it wouldn’t so damn weird. Plus, there’s even less buildup of any satisfaction of Rey confronting Palpatine like there is going from Luke confronting Vader. Nothing personal about it. Rey’s fear was being alone in the galaxy, not knowing her parents. Nowhere in these films was she afraid of Palpatine.