There is no version of the story in which Rey’s parents being the progeny of Palpatine are ‘nobody’. At the very least they have a claim to the remnants of the Empire, regardless of what Force power they do or do not have. Rey being the grandchild of Palpatine absolutely gives her a place in the story; it is literally a noble birth.
Rey throughout the trilogy is desperately searching for someone to validate her abilities and place in the story, and TLJ does the thematically necessary step of ripping that away from her. TROS gives it back on a silver platter.
Except that we very plainly see them on the run and making no claim on any of that. They literally are living as nobodies. They leave Rey (none to soon as they are murdered shortly after) on Jakku with Unkar Plutt. Rey is literally raised as a nobody and she has no idea her parents were anyone special. Palpatine’s reach was far, even after his death, and he killed his own child. The movie implies child, but clone has been suggested. But his child might not be much older than Luke and Leia. But in any case, Rey knew none of that. That is how Kylo got her to admit they were nobody. Before he turns around and in the next attempt tells her she is a Palpatine. It works very well for a progression to try to destabilize Rey and it appears to work.
It was obviuosly done for TROS and was not planned before that (or Trevorrow’s script would have something about it), but it works as a story progression.