Yeah I just realized that there’s really no way for Kylo to feasibly tell Rey anything about the dagger while they’re fighting, because if he notices that she’s holding it then he instantly should know that she is on his Destroyer. And we know he disengages their conversation as soon as he knows where she is later on by noticing Vader’s mask. So it wouldn’t make too much sense for them to carry on as soon as he notices the dagger. Or, at the very least, to be surprised by saying: “So that’s where you are…”

I’m not sure that this idea would work beyond what Hal already suggested (reinstating that line). But I think a large part of the reason why people wanted that line removed is because she says it while simultaneously holding the Youngling Slayer 9000. Thing is, we already got a scary vision for that saber in TFA. Ya know, when she first held it! That’s how psychometry is supposed to work. In other words, I don’t think there’s any problem with the line. This is actually something TROS got right, and anybody who criticizes it is just nitpicking IMO.