THANK YOU for writing this. I've wondered if my ex was NPD or autistic, or neither, but just socially awkward and self-absorbed. I know that he did a Meyer's Briggs test and came up as INTJ (if you're not familiar, a lot of the patterns and habits correspond to aspects of high-functioning autism ... but this has been very enlightening.
My ex boasted that he was very empathetic, and I now realize he was higher in cognitize empathy and terribly low in emotional empathy.
I've silently rolled these questions around my mind, so thank you for the article.