It's completely believable that Sasuke would interpret the Hokage's stories under the aegis of his Itachi hero worship and end up protecting the village as a result. Sasuke's entire motivation is his screwed up relationship with his brother, first antagonistic, then with a kind of transcendent deification of his motives.

It would also be totally absurd right now if Sasuke was literally on board with annihilating the entire human race, no matter what his past transgressions are - transgressions that occuring during the throes of Uchiha Sharingan Brain Damage and while he was being emotionally manipulated by Obito. All is not forgiven, but there is simply no other choice besides moving against Obito and Madara at the moment.

I'd expect Sasuke to throw down with Naruto again as soon as Madara and Obito are defeated.