"of all the abilities that humans are granted by their birth this is the one you perform the worst" -- This seems like an odd comparison. Can you really compare my ability to, say, tell stories to 'mind-reading'? It's like comparing my ability to walk to my ability to jump straight up: I can walk for miles, but I can only jump straight up a meter or so -- a 1000:1 ratio -- but I do not feel particularly bad at my ability to jump.

I would definitely believe the AI, but I already believe it, if it said "humans are worse at discerning states of minds than they think they are" -- Paul Ekman said the same, with plenty of research to show how a bit of training can make you better at it. "It is obvious you are living in a simulation", as an easy comparison, is way stranger to me -- the above statement would not even rank in the "10 strangest things".