I was opposed to Leia telling Rey “You are family” from a writing standpoint because I thought it undercuts her journey and I still believe that, but I must say it made me quite emotional hearing that on the scene. Not only for what it means to Rey but because it made Leia feel more alive and present in the movie than ever before.
I would agree with you if not for the fact that Rey is clearly insecure about her self-worth after seeing that vision. Yes, Leia tells her that she is family, but logically that would only serve to make her feel worse about not telling her that she saw herself on the throne of the Sith. She believes that if Leia knew the truth about her then she wouldn’t be saying that.
Which is why I’m mildly miffed that Leia knowing all of this about Rey isn’t in this edit. Something like “Leia saw your vision, too” from Luke on Ahch-To. But I can live without it I suppose.
EDIT: Just remembered that we might be doing this for the new Rey Nobody edit so I might just be able to splice this change into v4.