Any particular link to rationality?
Not really, but I thought it hints at some important insights and problems. What if it turns out that certain races are more kind than others, how would such knowledge influence CEV? If there are strong genetic factors strongly determining such important human values as altruism and general warmth, the opposite could be the case as well. This all leads to the question, what does it mean to be human? There might be some incoherence if the psychological unity of humans does depend on as little as 25 genes. Therefore CEV could turn out to cause a minority of humans to suffer or be discriminated due to their extreme psychological otherness, because it ultimately has a bearing on their interpretation of ethical questions.
...coherent extrapolated volition is our choices and the actions we would collectively take if "we knew more, thought faster, were more the people we wished we were, and had grown up closer together.
If important human values are as strongly determined by genetic factors as shown by people with Williams Syndrome, then knowing more won't make the volition of different people with different genetic makeups converge.
Letting the future of the universe be determined by a quick snapshot of the different fraction of human demographic groups... The idea that the same provably friendly AI would do something radically different with the universe if its developed in the decade that Finns represent 60% of the world's population compared to a decade later when they represent 10% sounds very scary but plausible.
Link: abcnews.go.com/Health/friendly-extreme-meet-kids-adults-williams-syndrome/