If you look at the compositions of the teams John Hart has built before offense has never even remotely been an issue (whereas pitching, almost universally, has been), so perhaps he's confident in his ability to sniff out value and production in that arena. Presuming that's the case, the pieces still don't exactly fit; the Braves already possess a solid pitching core at the Major League level, have a decent amount of high-ceiling arms in the Minors, and own a rather pristine history of accumulating valuable arms from outside of the organization by a variety of means.
If the Braves move Justin Upton -- and I believe they will -- this team goes from a poor offense to a brutal one. And that's not even accouting for the real possibility that Gattis is gone as well. What scares me the most about this potential series of events is where it leaves the Braves even looking ahead to competitiveness in 2017. The farm system has about 5 semi-projectable bats in its current arsenal, and even if the team completely reshapes its draft/scouting strategies it could easily be 5-6 years before any of that talent sniffs the Majors.
Obviously we will find ourselves in a much better position to analyze the direction of the team after Hart finishes executing the first stage of his plan over the course of this offseason, but right now we have a lot more questions than answers.