True, but the conversation starts with Rey outwardly confessing her vision to Luke, whereas her lineage is something Luke has to coax out of her, it’s clear that carries a heavier burden to her in the moment, and is what’s convinced her the vision will become true. Saying Leia knew about the vision but not her lineague is a much less impactful revelation, since we can assume she believed, like Rey did before the rest of the movie, that she could overcome it by focusing on her Jedi training. You might as well just say Leia sensed her pull to the dark, or the darkness inside her, which would work for the Nobody cut, but for the Rey Palpatine version it makes more sense for the conversation to stay focused on the big reveal.