Forward movement is stopped.  It's not an EMP.   They can still target you and fire.  This was stated in the Mech Spotlight video posted on mech Arena's YouTube.  

But that is Bad for the mech 

It where much better when BLIZZFROST where an Epic mech then its ability where ok (for an Epic mech) 

Make BLIZZFROST to an Epic mech Plarium has done something like this before; Killshot and Panther were uncommon before

The slightest difference in elevation renders the icy grip useless.

Mechs 'can't move' yet they can move to turn and keep firing.  What a pile of marketing crap.  Plarium intentionally chose not to tell players there is no vertical capability to icy grip.  Even their spot light video cleverly hides that fact.  So much for just being open, honest and forthcoming with their customers.

Frozen mechs aren't supposed to rotate/move at all but they do...

I have Blizzfrost and my opinion on this is different. The ability prevents movement except turning and firing but also deals damage, increases self damage resistance and increases speed (and it works through walls). Making it yet another EMP with all these other advantages is obviously the wrong move.

Personally I'm happy with the mech's ability limitations. It's formidable without being overpowered.

That said, I completely agree with all the folks that are unhappy about the wording. The description should reflect the scope of the ability accurately, which currently it does not.

That is not how that works it stops your movement, not your turning those are two different things in spacial allocation.  They are not stunned or emp'd just held in one spot.  That's how the Mechanic was explained when they introduced it.  

Turning is movement. In the spotlight video, it says it stops mobility but can still aim and shoot. Mobility includes turning. Redefining the definition of motion doesn't make it true 🤦‍♂️if you're frozen, you're frozen...