Yeah. I saw that statement too. I think the statement went further in suggesting the director 'thought' it to be true at the time and so I point out the following:
It should be noted too that there is a different director for the last jedi (Rian Johnson) than who directed/will direct (J. J. Abrams) both the force awakens and the last movie of the trilogy.
On the topic of time travel in Star Wars, I did find that time travel does exist in Star Wars and not just because of time dilation. Most of the 'regular' time travel is because of hyperdrive malfunctions, shielding malfunctions that protects against time dilation, travel too close to intense gravity wells, etc.
The real 'time travel' occurrences I see included Mace Windu going to a particular temple to return a particular artifact that was placed in Jedi safekeeping thousands of years ago. This ancient civilization that had died out I think long ago had a prophecy and idolized this particular hero. Well, Mace returned this artifact to a statue that weirdly enough had a uncanny resemblance to himself. Once he placed the artifact upon the statues outstretched hands, Mace was transported thousand+ years ago onto an ancient battlefield where he helped turn the tide of battle. At some point, he returns to his present and when he informs the Jedi Council, he is told that the Jedi were awaiting the fulfillment of this prophecy and had believed it to be him and therefore had sent him to complete the loop.
I think there are other instances of 'real' time travel too but not much.
Well, I can believe Rey is her own Mother, but that is consistent if she is a Clone but that doesn't require Time Travel. And, I could accept that Rey will have some power over time itself per darside Mirrors. I'd adapt that ability and say she could pass that ability down to her descendants.
So, I'll apply my Murphy/Marcone theory onto Rey/DJ. In Dresden Files, Marcone descends from Mab/Murphy with time travel in the mix where Marcone finds himself around a time of Murphy's relative 'youth'. DJ descends from Rey with time travel in the mix where DJ returns to a time around Rey's relative 'youth'.
As to bringing balance to the force, I've already pointed out the big bad in the expanded universe which is now legend and not canon but may be refashioned into it again. The big bad is Abeloth, a 100k year old female/force entity that was corrupted when she did what was forbidden. She was imprisoned within a black hole cluster where safe navigation within the cluster was extremely difficult. She had insanely intense ability to influence the force and those using it to cause those using it to suffer force psychosis, the desire or urge to go all homicidal. So, she is or could be an indirect cause of Luke having temporary homicidal ideation with respect to Ben, Anakin's mass murder of the Jedi on Coruscant, etc etc. Luke's journey to the island and him cutting himself off from the force could be a way to protect himself from being influenced again by this identity that is so strong within the darkside. It should be noted however that Abeloth bathed herself in both the 'Wellspring' of darkside and lightside of the force.