I think #1 is what happened, but not on purpose. They didn't feel the need to spend big on pitchers last offseason because they truly thought (as was reasonable) the 2017 rotation would consist of Teheran, Wisler, Folty, Newcomb, Blair and whichever other young pitchers earned a shot. With those guys heading the rotation on the cheap, the Braves could have afforded to sign some impact guys like Ces, or trade for someone like McCutchen or Longoria.
When Blair, Newcomb and Wisler failed to progress, and Folty only progressed slightly, the plan had to change. Instead of "going for it" in 2017, they have to make measured improvements that don't hamper the team from competing in 2018 and beyond, yet made it look like they were "trying". Kemp was such a deal. Mac and Shields would be such deals. As would signing Castro, De La Rosa or a non-QO guy for 3B on a 2-3 year deal.
I don't think the plan ever was or will be to tie up big resources into a single starting pitcher. The Braves will never commit the prospct assets to trade for a guy like Sale, nor will they ever commit the cash to sign a guy like Price, or even Cueto. They will, and should, look to bring in young guns from within the system, trade them away at peak value, and then bring up the next guy in line. They have set themselves up to do exactly that, and they should only sign a FA starter to a 1-2 year deal in the event they need to fill in a gap due to injury or lack of prospect progression.