One thing that the Atlanta Braves talk about a lot is the culture that they have established in their clubhouse. Nearly top to bottom, the guys that they have been bringing in are all-in on the culture of winning and maintaining harmony in the clubhouse to that end. There is a reason why the Braves have been able to sign guys to all of these team friendly extensions. Guys want to play in Atlanta, know they are going to get taken care of, and there won't be any unnecessary drama.
Unfortunately, the players that come available aren't always the best human beings. The history of baseball is loaded with guys that were considered clubhouse cancers, but who had the ability to play baseball well. However, general manager Alex Anthopoulos is not interested in such guys whatsoever. When asked recently as to whether or not he would consider signing a guy who is a jerk, he not only pointed out how much he values character, but he also gave Braves fans an interesting mystery to solve.
The Braves don't like to sign clubhouse cancers and the team is better for it
First and foremost, this answer is pure gold and speaks a lot to why the Braves have been so successful under Anthopoulos. There have been plenty of attempts by teams in the past to buy championships only for big egos and loud morons to infect the clubhouse especially when things aren't going their way. Atlanta has done a terrific job of adding talent in free agency, trades, and through player development that simply get it.
However, it is also fun to wonder about who AA could have been talking about when he said that a current Braves player essentially nixed a trade deadline deal this past year because the trade target's character was not something the organization wanted any part of. His answer also eluded to the fact that said player would have only been around for a couple months, so this player was probably (but not necessarily) eligible to be a free agent this offseason.
Tommy Pham has been thrown around as a possibility on social media because he is an easy target given his general demeanor and the fact that he slapped Joc Pederson before a game over a fantasy football trade. That said, the actual fit for the Braves at the deadline last year is a bit dubious there given that they were more in the market for pitching at the trade deadline than anything else. If one was wanting to take up AA's challenge to reverse engineer the options, you may be better off looking at free agent starters and relievers and cross-referencing them with Braves players who have played for other teams.