So the devs. had proposed a three second cooldown for pyroblast on the patch 5.1 PTR.
The reason alleged for this cooldown was first given by a tweet from Ghostcrawler, who claimed that fire mages being able to hit other players with "7+" pyros while shattered was "dumb." Several blue posts after this confirmed that the nerf was intended to remedy alleged fire "burst" in PvP.
The problem with this was the the alleged issue they were attempting to remember is almost 100% fiction.
First, it is literally (yes, *literally*) impossible to get off 7+ pyroblasts while a player is affected by shatter. There aren't enough global cooldowns. Second, even if "7+" is an exaggeration, and the devs were concerned about chaining 4 or possible 5 pyros, that essentially never happens. This is because the only way to reliably chain 4 pyros, is by using a combination of Presense of Mind (makes a cast an instant cast) and Alter Time. But fire mages do not take the Presense of Mind when they PvP, they take scorch, which can be cast while moving. Third, there aren't very many fire mages that PvP; the overwhelming spec selected for PvP is Frost.
And this doesn't even address the fact that other classes and specs have *more* burst than fire, including the more prevalent frost mages.
So again, the alleged reason for the Pyro cooldown was pure fiction.
We've been attempting to get an answer from the blues that makes sense, but they had gone completely silent for over a week.
Today, I am happy to report, Ghostcrawler walked back his previous tweet: