Azure, the cloud compute platform used by the Xbox One for behind the scenes server-side offloading of graphics and other processing, can apparently be used by any platform and for any game.
Phil Spencer answered a fans question about the upcoming Titanfall 2, which is going to be a multi-platform game. He said pointedly the platform is open to absolutely everyone, which is rather generous that Microsoft would allow such, even if the game is a PS4 exclusive.
Azure cloud compute is open to literally anyone who wishes to set-up the service in their game, from AAA to indie developers. All you have to do is rent the appropriate servers and install the back-end software that you wish to offload with, and tie it into the games code. There are plenty of third-party software solutions to install that can take over compute loads for all kinds of things. One can even use Amazon's AWS or Google's cloud platform as well.
But it's still nice that it's awknowledged that Azure is open to everyone and every platform, regardless of exclusivity or not.