Maybe I need to play the Balance preview to get a better understanding, but the Churchill still requires 9 hits from any source of 160 damage(most common and found on the majority of AT/tank cannons) and it can still deflect shells from PIVs.
Against PaK40/puppchen, durability of new churchill is exactly the same as durability of KV-1 on average. Only difference is, its less prone to RNG, which means you will NOT have lucky escapes as KV-1 can nor will the speed allow you to.
No one in his right mind will pay T4 level costs as brits for slower KV-1.
It also comes with Anvil engineers who can put it back together very quickly and while slow and vulnerable to explosives, can put up a fight when given LMGs ontop of their Vickers.
Which will not make up for the churchill overnerf as cheaper to reinforce Tommies will be more then enough.
I'd rather see its rear armor being vulnerable then front one being stripped to medium tank level.
This thing was more durable then Tiger I and right not its a slower, stock KV-1.
I don't see this heavy nerf making it to the patch and if it will, churchill will disappear from any game mode for the sake of the superior in every single aspec(survivability included) Comet, which can take exactly the same amount of shots from PaK/puppchen on average, but is much faster and has much better firepower.