“You were right” leads into the next line better, I think. If he says “I see them,” I’d expect the next line to simply be “Your parents.”
But he practically does say that. “I see them … [insert description of what he sees about her parents]”. He later tells Rey herself to “see them”, which leads into the first vision. So by having him say this line it’s clear that through their dyad they are capable of experiencing the same vision/memories. I think that’s a really cool concept that isn’t clear in the original. (Heck, I’m pretty sure the original implies she’s getting the visions from the dagger which is kinda dumb).
Besides, there are a lot of other people who agree that “You were right” simply doesn’t sound natural. No offense to Pappa of course, he did his best there, but why would you use an unofficial line if an official one works just as good if not arguably better?
Either way, I suppose this may be another thing I’ll have to do on my own somehow. Lots of other LEGO lines that I think would work well in this film. Might just have to make the Ascendent LEGO cut 😉