No. They still blame the Indians and John D. Lee (who was acting under orders by the Cedar City Bishop and possibly B. Young himself).
The Mormons I know would deny Brigham Young's involvement in the Mountain Meadows Massacre if Brigham Young himself came back to life and confessed.
Actually that is not a topic which we discuss much because I don't think there is any definitive evidence to prove Brigham Young's involvement or approval. I find it difficult to believe that given the iron rule Brigham Young exercised that something this big would have occurred without his knowledge and approval. Besides, it became apparent quickly that my Mormon friends wouldn't accept ANY evidence which implicated Brigham Young.