Coming from one who is always trying to find new fun ways to increase my loadout and now has metagame designed around him - this does not break the game.
This specific blaster only really trumps other blasters in pure ammo consumption. BOOM Nitrons, RS, Vulcans all can get in the same territory of ROF with the 1,3 blasters having similar capacities.
It all really comes down to this.
Look, how many times have we seen the HvZ community react to some upcoming/new quantum advance in equipment with doomsday predictions for the game? Or look back on a recent period of continuous improvement and worry over game balance in the future? It was one hell of a lot of times. Too many to list. Tons of product releases and hobby developments. It has been happening all along the road from 2005 to 2015, during which time the equipment has evolved to something superior to the wildest dreams of the early players, let alone what people were once worried about "killing HvZ".
The metagame of HVZ has evolved over the years has grown and changed with what equipment the players have available. Blasters from the Raider to the Rapidstrike were all thought to kill the game when they first entered the market - they didn't. Zombies have always been able to kill players based not on their equipment but their own ineptitude/inexperience. Every player now has the ability to go out and purchase/build a high ROF rifle, but it becomes useless to them in the game if they aren't familiar with it and its habits.
My mod teams have grown around me and seen what kind of firepower fully modded blasters can pump out, thus they let the game evolve. It is not due to my equipment that I am difficult to nom, it is due to my ~40 games of experience and awareness.
We can also see much of this manifested in the fact that Sock Ninjas are still around in the game. Equipment will never break the game, but rather provide diversity to the playstyles.