The other morph of Clench is Reach, which does not have CC either.
Al Mualim: Before you go, I have a question for you.
Altaïr: Of course.
Al Mualim: What is the truth?
Altaïr: We place faith in ourselves. We see the world the way it really is, and hope that one day all mankind might see the same.
Al Mualim: What is the world then?
Altaïr: An illusion. One which we can either submit to, as most do, or transcend.
Al Mualim: What is it to transcend?
Altaïr: To recognize nothing is true and everything is permitted. That laws arise not from divinity, but reason. I understand now that our Creed does not command us to be free. It commands us to be wise.
I think they removed it because they couldn't make it work reasonably with block. When you'd get stunned because you needed to block before the projectile animation was visible... bet ZOS couldn't fix that for some reason.