Long L70 - 7.5cm from Panther and Jagdpanzer IV was indeed buffed massively, but a gun that has almost 200mm of penetration power should have absolute anti tank power, which it didn’t before the update, as a matter of fact the panthers gun had practically no post pen damage.
Now, as someone who owns a couple of premium vehicles like the Stug III on Normandy and the Jagdpanzer IV L70 on Berlin and the Jagdpanther, I have however also noted that many calibers, which those vehicles were immune to, are now capable of penetration.
Before that update 7.5 Shermans and Jumbos had practically no real way of defeating my Stug, while both Jagdpanzer IV and Jagdpanther were immune to T34 85s.
This has changed, it now indeed feels like many vehicles had their armor nerfed.