Activision has had an exclusive marketing deal with Sony's PlayStation consoles for a while now. For example, in 2019's Modern Warfare reboot, Spec Ops' Survival Mode was exclusive on the PS4. Meanwhile, for 2020's Black Ops Cold War, only PS4 and PS5 owners had access to Onslaught while also getting exclusive bonuses like loadout slots and double XP weekends, among several others.
So, it shouldn't come off as a surprise that PlayStation owners will get exclusive benefits for the upcoming Call of Duty title, Vanguard.