While Diablo 4 may be arriving on Xbox Game Pass in the very near future, players wanting to experience the action RPG through the service will need to jump over one minor but irritating hurdle. Serving as one the first Blizzard Activision games to land upon Microsoft's subscription plan, users are eager to play the game for "free." However, much like most AAA experiences, users will need to make an account for a completely different service if they want to actually play the game.
https://screenrant.com/diablo-4-xbox-game-pass-battlenet-login/