I've certainly had some potential ranged Impact ideas in mind for the future, but this isn't just ranged, you're talking AOE!
Technically Hunters don't have much in the way of good coverage anyway--their core is fairly exposed, it's more the fact that they're hard to hit in the first place. So yeah an Impact AOE weapon can overcome that, but so can any AOE weapon, really. That's why explosives are so effective against them--in the face of explosives they're not really any better than your average Grunt!
Still, I like the theory of it. Concussion Bomb Launcher sounds like fun. Of course I wonder how much that would tread on EM AOE's territory, since if this thing is good enough it could technically start corrupting whole squads to death pretty quickly!