Removing his e-flash would literally push him into unviability unless they they give him a better tank steroid.
Not only does tank grag rely on e-flash for quick initiations, the mystical AP gragas would lose a significant amount of reliable damage.
You can argue that Camille's is only single target, but she has a guaranteed ult-hit AND true damage out the ass.
You could argue that Shen's is really small (which it is, they should really enlarge it) but his ult is one of the strongest abilities in the game and even as a tank he can bully most lanes early due to his ridiculous q damage.
I'm all for narrowing his e hitbox because it irritates me even when I play him, but they really shouldn't touch the synergy between his e and flash.