for folks wondering why we dont just port the whole game realtalk:
While I personally believe its an evergreen masterpiece of whimsy and wonder, it would be a year old by the time Forge released, and given the architecture, cloud, matchmaking, etc etc etcetc differences between platforms, it would be neither trivial to port, nor uncompromised in that process, given it was designed with targeted Xbox One perf in mind to begin with.
We have to work on things that are sustainable for the studio, and make sense for long term planning. This is something we wanted to do for Xbox One forgers for a long time and is of course an extension of the existing suite. This is a sustain beat for Halo 5 on Xbox One. Its certainly a big bonus that PC creators and players will get to play around in that sandbox, but thats not really the primary purpose of the tool.
We knew thered be latent demands for a full version of the game (as there have been since H2 on Vista), but neither the time nor the finances make sense this far along the calendar. Halo Wars 2 will be a more palatable and straightforward example of the fact that we take PC gaming very seriously as an organization and a studio.