I am afraid you don't realise how much OP CCimmunity will be for sents. Imagine having cc immunity during gore/pre slash, a sent can do 17-18k of damage on a single target within its duration.
Oh god please no, I don't want to run around and roflstomp everyone in a WZ, that's no fun. I like how in the fact I have to run away when I see a sniper in a WZ. No to cc immunity.