It has become fairly obvious that extenting players before they hit free agency is a much better policy for clubs (especially smaller and mid market ones) than playing in the deep waters of top tier free agency. The Braves have done well with deals to McCann, Freeman, Simmons, Teheran, and Kimbrel. There will always be some deals of this sort that don't work out. But others become absolute bargains (McCutchen, Altuve) for the teams involved, allowing them to significantly expand their competitive windows.
The main point is that as a group these deals work for the clubs. So you want to extent just about every possible candidate. This allows the law of averages to work in your favor. And you want to strike three or four years ahead of free agency, because these kinds of deals get harder to reach as a player gets closer to free agency.
With respect to the Bravos, it seems to me this off-season will be a good time to get something done with Vizcaino and Inciarte. Then moving forward, any prospect that develops into a decent major league regular should be approached with an extension offer. I think we should even do this with pitchers, who are more risky. The risk-return still seems to favor the clubs with them, although I think it is smart to try to tack on an option year with pitchers as we did with Teheran and Kimbrel.
Extenting the yute as they establish themselves in the majors is the best way for a mid-market them like the Bravos to achieve their stated goal of being perpetual contenders.