I find the matter unclarified. Given the large variability of the Pleistocene climate and habitat (that Kurzban mentions), what does the quoted definition of the EEA mean? "A statistical composite...weighted by frequency and fitness-consequences" looks pretty much like a time and a place -- just an average one instead of one asserted to be the actual environment, habitat, and social structure over the whole Pleistocene. Both concepts ignore the variation.
Did you read the whole post? I thought it was relatively clear - if I had to summarize it in my own words, I guess I'd say something like "the EEA is not a specific physical or temporal location, but rather those properties in the environment of the organism which have stayed invariant over very long periods". It doesn't "ignore" the variation, it's specifically defined via the complement of the variation.
If it's worth saying, but not worth its own post, even in Discussion, it goes here.