The datamined information isn't on its own, though. This conversation compliments it fairly well. Again, this is an assumption based on past trends. And people just weren't talking about Aethas because the Silgryn/Liadrin conversation was more easily related to the on-going conversation about subraces. It makes sense we didn't randomly talk about Aethas' conversation's relation to the wound when the wound wasn't relevant, but I get you.
On to your point, I think you're probably right. I mean, Khadgar basically straight up says that powerful forces will want to claim the blood, and Jaina and Azshara will probably feature heavily in 8.0 so it does make sense.