According to writer/director Rian Johnson, yes.
This is covered in an interview he did with The Daily Beast.
While he doesn't come right out and say, "yes, her parents were junk-traders", he acknowledges that she is a nobody and comes from nothing.
That was the idea, says Johnson. “That seemed so appealing to me. I mean, that really seemed like something that was genuinely exciting,” he says. “I think that actually gets back to the roots of what makes Luke appealing, because when you’re watching that very first movie, A New Hope, you have nothing in your head about him being the Chosen One or his lineage or this or that. What you see is a kid who’s in the middle of nowhere on a farm, who’s a nobody, who feels like he’s never gonna get out. The same way that when we’re kids on the cusp of adolescence, we feel like we live in a really small world and, oh man, am I ever gonna grow up? Am I ever gonna have these adventures that I keep hearing about on TV?”
“He’s on the cusp of that,” he says, “and then he jumps into an adventure and is pulled into the center of it. That, to me, is the essential appeal of it. And to me, the notion of Rey being a nobody and coming from that and then suddenly finding the power in herself to be central to these big adventures? That’s uniquely Star Wars.”
“I do like the notion, and I think it’s something that’s gonna be necessary, that we’re pulling it away from the idea that [the main Star Wars saga] is limited to this small club of Skywalkers,” he continues. The big reveal had dramatic implications too. “Rey is our protagonist and the truth is, in the story, the toughest possible thing for her to hear is, you know, you’re not gonna get the easy answer that you’re so-and-so’s daughter, this is your place. You’re gonna have to stand on your own two feet and define yourself in this world. And you always wanna throw the hardest thing at your protagonist.”
To be fair, it seems as though each writer/director is being given a fair bit of leeway, and it is possible that the next film by JJ Abrams will retcon this, but for now the word of god is that Kylo Ren was being truthful.