I agree we were overpowered this expantion.
As a die hard affliction warlock, KJC was for me the only way to live. This tier forced us to move. Constantly. And our output was based on the fact that we COULD move.
Think of horridon, council etc. If we are snared to the ground we can't MG. And if we dont MG we don't DPS. FellFlamme is a double DPS-loss for affliction. It cost a lot, refresh (and downgrade if you're unlucky) your dots and hit like a wet noodle.
If the next tier is more "root-friendly" then the KJC nerf will hit us less badly, but I doubt it will happend.
So what they should do is, I think, make our filler spell (MG, Inci/immolate, ShadowBolt) castable while moving and make our "big" spell (Haunt, Chaos bolt, Soul Fire) castable only when rooted on the ground. It gives us mobillity and forces us to actually think of our placement before casting.
Nothing is more disheartening as destruction than a "YOU HAV ONE SECOND TO MOVE NAOW OR DIE LAUL" while your chaos bolt has 1.4s before launching...
TL/DR : having to think of our position isn't bad. Casting our filler while moving isn't bad.
Oh, and I want my metagem please