I feel I should point out that those two things are not mutually exclusive. RNNs are, after all, a mechanism for learning conditional probabilities.
I think the confusion comes from Google itself, who used the term "Statistical Machine Translation" (SMT) to refer to "Rule-based SMT". Both methods are statistical.
SMT as a term of art in the translation field means rule based SMT... it's not a google particularity, I see the same usage in both industry and academia
