My understanding was that Zuvio had a scene in daylight at the Outpost. We’ve seen stills.
They absolutely could leave Rey’s lineage as it stands at the end of TLJ. RJ said that JJ and he discussed the parentage, he was told he could do whatever he wants. That either speaks to JJ not caring where it went or a plan he had to do something in the 3rd film (which he became responsible for after the fact).
These are the latest comments I have seen by RJ about it and when asked point blank about it, he waffles:
"So, can I just make the statement, that’s who her parents are? They came from nothing, they’re buried in the desert, is that for sure?
RIAN JOHNSON: That’s what Kylo sees and that’s what he tells her and I think he’s not lying in that moment. That’s what he saw and she seems to believe it when she hears it. I don’t want to … I’m not writing the next film, we’ll see how they handle it going forward, and as we all know in these movies, there’s always a certain point of view that’s involved. But, for me, I’ll tell you that was the … I can understand why that answer doesn’t feel good. It’s not supposed to feel good. It’s supposed to be the hardest thing she could possibly hear in that moment."
Even when he doubles back to his own decision, he won’t just say “Yes”.