Activision make a killing from selling DLC & Season Passes from their games like Call of Duty. Not sure why they'd give up free money from a single toggle switch with no extra work.
Unless out of spite, like when Snapchat banned third-party clients for Windows Phone (like 6snap) and accounts using it (I'm still raging that my 'benbristow' username got banned and now I'm using 'benbristow1' because of that).
Fun fact: The guy that made 6snap (and other 6 prefixed apps like 6tin (Tinder)) (Rudy Huyn) was hired by Microsoft and is now one of the leads behind the updated Windows 11 Store app