One thing about acquiring new players in the offseason, whether it be via free agency, the trade market, or the Rule 5 draft, is that you have to figure out what you are going to do with the current roster, especially when said roster is full. At the non-tender deadline, the Braves decided to tender contracts to everyone which meant that their 40-man roster was at 40 players (otherwise known as full).
The Braves have been mentioned on the periphery of a few rumors down at the Winter Meetings, but they did not have the roster flexibility to just add a player (even in the Rule 5) without a corresponding move.