Microsoft Gaming CEO Phil Spencer recently stated during an interview that he can't rule out Starfield releasing on multiple platforms.
Spencer responded to a direct question about the title in a recent interview on Save State Plus with Destin Lagarie, who asked the Microsoft gaming head if he could confirm if Starfield will remain an exclusive Xbox/PC title. Spencer replied with, "No," and went on to reiterate a sentiment that has long been held by himself and Xbox as a whole.
"There's no specific game... this kind of goes back to my red line answer. There's no reason for me to put a ring fence around any game and say this game will not go to a place where it would find players, where it would have business success for us."
Spencer goes on to explain that Xbox's strategy is to allow for Xbox games to be available wherever they can be, especially if that platform is able to drive more business for the company. The Microsoft Gaming CEO does state that Game Pass will still remain an important component of the Xbox ecosystem.

"What we find is we're able to drive a better business that allows us to invest in great game line-up, like you saw. And that's our strategy. Our strategy is to allow our games to be available, Game Pass is an important component of playing the games on our platform. But to keep games off of other platforms, that's not a path for us. It doesn't work for us. What we're doing now, we think really enables us to build the best platform for the world's best games," said Spencer