I’d personally prefer to make their struggles with the dark distinct so that we don’t already know if this is something she can overcome. Otherwise, we completely remove the stakes of her confrontation with Palpatine at the end. It also opens the door for people to dismiss what Kylo says about the Skywalker bloodline specifically as a lie from Palpatine to manipulate him, if that is what they wish. Luke only really has the opportunity to talk about Rey’s own background in his scenes anyway, and how Leia knew something about it, given what we have to work with.

I liked my approach of having the Skywalker bloodline be 50% light and 50% dark, but Palpatine still initiated Anakin’s conception. They are quite literally the “balance” of the Force itself, because they are an unaltered creation of it. It works as a prototype, if you will, that he would initiate, see as flawed, and seek to “improve”. So with Rey, he figures out how to impart his own nature onto a Force-created being. A spiritual “Palpatine”. She is more susceptible to the dark side than the Skywalkers. All of this lines up with canon, and it needn’t be mentioned ever again after this point. The point of this revelation is to make you watch the previous movies again with this altered perspective, NOT to see what comes next in canon for the Skywalkers. We already know Anakin, Luke, Leia, and Ben all have a great propensity for both the light and the dark and will continue to going forward in canon. Hell, Anakin’s life was literally spent 50% as a Skywalker and 50% as a Sith. In Rey’s upcoming movie, her continued struggle with the dark side as a “Palpatine” will almost certainly be touched on at some point. It’s important that this wouldn’t simply be a retread of the Skywalkers, whom according to you we should be moving away from. So we have to make it exceedingly clear exactly how they are different (greater draw to the dark side), while also similar (both a product of the Force itself, at the request of the Emperor).