Xclusive Ace made a video about this yesterday. Yes, the menu stats show differently, but the damage and rate of fire are still the same. He was testing this in multiplayer and there was no difference. What actually changes is the recoil on some guns. It can lower recoil on some weapons, but I just want to get the news out that menu stats are broken right now if you load it into a Warzone match before you start multiplayer and zombies.