Lots of companies have products that exist just to compete with a rival’s product and keep the pressure on them, I’m sure Microsoft has plenty of products that exist just so they have the “you know we could drop this deal we have with you at any point and use our own version, so offer us a good deal”. I imagine they’ll keep the xbox around even if the likes of Sony and Nintendo do support game pass just so Microsoft have always got that bargaining chip of “alright then, we’ll run it on our own machine” if the others decide they want to change the terms of the deal.