When it comes to attackers
-I.Q
-Thermite
-Thatcher
All feel like must haves. I.Q is very crucial to deal with Valkyrie
As far as defenders go,
-Rook
-Valkyrie
-Jager (unless its Hostage)
Valkyrie singlehandedly made I.Q relevant
I can see Valkyroe getting a nerf, like Frost. Reducing the effectiveness of the shotgun or removing her C4, or maybe even her camera count to 3 instead of 4
4 seems a little over the top to me tbh.
I hope we see some upgrades to existing operators to make them viable. Tachanka's upgrade is a start.