You're conflating two different things that Kylo said and assuming there is a connection where there might not be one at all.
After Rey tells Kylo that she's seen the future and that he will change sides, what Kylo actually says is closer to:
I've seen something too, and because of what I've seen I know that when the time comes, you will be the one to change.
In that line he doesn't mention her parents. He does mention that he knows who her parents are, but not in the same line; it was a separate thought. What kylo might have been referring to was the scene where she and Luke fight and it does look like she's turning to the dark side immediately before leaving Luke's island to seek out Kylo.
If you care to speculate, it is made clear during the movie that one of the major factors in Kylo turning to the dark side is the pain his uncle Luke inflicted on him by not trusting him and trying to kill him, so it makes sense to speculate that Kylo would think that her parent's abandonment would have a similar effect on Rey.
So, is he lying? I think it's safe to say, no (but again, this can only be speculation; there's no way to know for sure). If he was lying he would have said what he wanted to say when they were talking via the force (when their hands touched). If he was lying he wouldn't have waited until later to reveal the lie since he couldn't have known they would meet again.
According to this website, Johnson says it's not a lie:
While Abrams (who is penning the script for Episode IX with Argo’s
Chris Terrio) could conceivably retcon Kylo’s revelation as a lie, as
it stands now according to Johnson, it’s true. All of it. Rey is a
hero who comes from nothing—just like Finn and Rose and Poe. It’s a
welcomely populist rejection of the idea that the fate of the galaxy
hinges on Skywalkers — people born special and considered elite by
virtue of their last name.