Troy Baker will indeed be voicing Nathan Drake’s brother in Uncharted 4: A Thief’s End.
Troy Baker announced on Twitter that he is the voice of Drake’s big brother in Uncharted 4.
"Good to see you're alive, little brother." Yes, that was me. Damn proud.
— Troy Baker (@TroyBakerVA) December 6, 2014
Troy Baker is one of the most prolific voice actors in the games industry. Just the past couple of years he was Joel in The Last of Us, Talion in Shadow of Mordor, Pagan Min in Far Cry 4, Booker DeWitt in BioShock: Infinite, and many more.
You may also want to watch Uncharted 4’s impressive demo to catch a glimpse of his talent.