Um, he's still emphatically not a moral relativist as usually understood; don't you remember the metaethics sequence? The conclusion that

(A) morality is essentially anthropomorphic rather than universal,

doesn't imply that

(B) we should become indifferent to the content of that morality.

ISTM that strict philosophical definitions of moral relativism tend to center on A, but that most of the conversation around moral relativism assumes it means B.