I expect that comes from the contrast and synthesis between how the author is anticipating things will develop or be explained, versus what the other person actually provided and trying to understand their thought process.

What happens if the reader no longer has enough of that authorial instinct, their own (opinionated) independent understanding?

I think the average experience would drift away from "I thought X was the obvious way but now I see by doing Y you were avoid that other problem, cool" and towards "I don't see the LLM doing anything too unusual compared to when I ask it for things, LGTM."