AND I think a good question is "Will Significantly more fans show up to see a .500 team as opposed to a 70-92 team?"
The Braves were bopping along at about 2.3M avg annual attendance over the last few years and fell to 2M this year. That's about a 15% drop. If there is another 15% drop in 2016, that laves them at 1.7M attendance. Now, the Braves in 1989 were averaging less than 1M fans a year but that was before 25 more or less prosperous years and a explosive growth of metro Atlanta. So what is the attendance floor? I would think 1.5-1.7M is probably it.
However, since they are moving into the new park and WILL get a novelty bump from that, even if they are the worst team in baseball in 2016 AND 2017, I don't see attendance falling much below 2M which is what it is right now. So, attendance, per se, isn't the concern IMO so much as merchandising, sponsorships, selling the boxes and overall valuation of the franchise.