That would be nearly unprecedented in the history of MLB prospect "groups".
The first wave of Top 100 pitchers from the rebuild consisted of Folty (#59), Wisler (#35), Jenkins (#94), Blair (#40), and Newcomb (#24). Going by historical averages, the Braves would have been lucky if 1-2 ended up with 3+ career WAR, and 1-2 more ended up posting 0+ WAR. Folty looks like he will be the lone 3+ career guy. Wisler busted, Blair is busting, Newcomb is on the road to bustville, and Jenkins is a AAAA arm.
Before the rebuild, the Braves had 3 elite pitchers in Teheran (#5), Delgado (#35) and Viz (#40). Odds said they would be lucky to have 1 guy produce 3+ career WAR, while the others would produce almost nothing. Teheran turned into the stud (13.4 career WAR), while Viz (0.6 career WAR), and Delgado (1.7 career WAR) have carved out mediocre careers as BP arms.
There is nothing special about this current group of pitching prospects, just like there was nothing special about the Teheran or Folty groups that came before them.
However, it should be pointed out that Teheran was on a completely different tier of prospect status than anyone else mentioned here (though Allard may push to that level). Top 10 pitching prospects have a MUCH better rate of success than the guys ranked #25+.