The thing with her parents is a good example of meta-narrative wrecking narrative, actually.
There's very little to go on in TFA to suggest the identity of Rey's parents matters. IIRC there's one short scene which mentions them, but in no other way does it appear important, relevant, or interesting. Okay, fine, they don't matter and I'm cool with that.
Then apparently mass fan speculation came out. Okay, everybody thinks she's related to somebody.
TLJ comes out, and it's clear the writers knew about this speculation, because now suddenly it's kind of relevant. Not actually relevant to the main plot, or any of the relationships in the movie (other than Kylo Ren, but it's not relevant to him so much personally), and we get a bunch of screen time devoted, and.. what's made of it? Seriously, what role does any of it play in the movie? What would be lot from cutting all of it?
Nothing. Because it actually was not part of the narrative, it was part of the meta-narrative. The scenes come and go, and nothing happens of it, besides the characters doing something they would have done anyway. It felt like the writers wanted to say "lol it don't matter who they are, stupid" to the audience. I felt they had wasted my time with unimportant ****.