I would propose to rethink the take on the PvP side of things. If any, cost of CC needs increase, not the counters.
We are already in a stage where things like bombard spam, WB spam, fear spam, are the most criticised game mechanics on the pvp forum. This change, in conjunction with the given statement of "slight cost reduction for abilities in general" is again the opposite of what many, if not the majority of pvp players have asked for.