I'm kind of in love with the idea at the moment, we're in idea-honeymoon phase. It's such a simple and completely elegant reversal. Kellhus was wrong the entire time. The whole time he spent gloating to himself about how deceived everyone was and how superior to them he was, all that time, he was the deceived one, and they were right, knowing more about him than he knew about himself. It completely upends all readerly expectations, and it would make you completely reinterpret most of the text without changing any of the protagonist antagonist structures or beliefs, it makes you see Earwa and its characters in a new light while alienating the reader from kellhus and his blinkered limitations. It makes the ubermensch less than a mensch.

btw. It works with BBT as well. Kellhus gets an instant, FTL, read of someone's thoughts inscribed upon their soul. this bypasses his consciousness and then tells him that he saw x, y, z in someone's face's muscle twitches, because this is what Kellhus expects to believe, that is what he believes, but it's all just pre-conscious--a darkness--happening BEFORE he gets to believe he had a conscious thought.
I feel like there is a connection in the above paragraph that should cause it to fit with the No-God is reverse-agnosia as well, but I'm not sure how to connect the dots.
If Kellhus has been reading souls and not faces, and the whole face reading thing was just a delusion of his consciousness, then I also feel like that fits in with Serwe's heart and Ent's explanation, what Kellhus does in pulling out the heart bypasses his consciousness exactly as his soul reading bypasses his consciousness, it's a thing he does without his consciousness getting it. Note how his conscious mind thinks it is separate from his bodies action preceding the event, and note that his conscious mind explicitly does not mention Serwe's heart as an example miracle to Moenghus. It is an event that challenges and shatters his own notions of himself, so he avoids thinking about it, like Akka avoiding thinking about how he got Inrau damned, or Esme avoiding thinking about that she sold Mimara to slavery; classic human failure.