Under the current CBA, but the new one will almost certainly require a player to be in the minors for much longer to gain the extra year of control. If the are ready they will be on the big club. The Braves have never played the service time game, so it's pretty naive to assume they will suddenly start doing it all of a sudden in 2017 with a GM that is pretty much an extension of JS and Hart.
And PS - any rosterbation post that has Cumberland as the catcher in 2018 forces all other thoughts to be immediately dismissed.