As I mentioned above, this seems to be a Benioff and Weiss addition to the canon. The very first line of the post is that the theory could be true because I wouldn’t put anything past Benioff and Weiss. Those expository scenes are all from the show not from the books.

I believe they bend GRRM’s exhaustively written and thoughtfully considered work into pretzel logic on a weekly basis. I give them credit for being amazing visual thinkers and creative minds, but they are awful at the logic.

Another possibility is the difference between greenseeing and green dreaming, which isn’t well explicated in the books and creates a bit of wiggle room. However, green dreams still are not time-travel.