Back in May, we saw a former Halo dev make his move from being the Studio Head of External Development at Microsoft to working with Microsoft's Mixed Reality team. At the time, it was said the dev would be working on educational games.
Perhaps when they said 'educational' they meant educating people on Halo (though this devs connection to the announcement has not been explicitly stated). Microsoft has announced that a mixed reality Halo experience will be releasing on October 17th.
Halo Recruit will not be a full-fledged Halo experience, but more of an introduction to the series. "It's a fun, brief introduction into the world of Halo," said Alex Kipman, Microsoft's Mixed Reality head. "You'll see several iconic characters in mixed reality for the first time."
Sounds like we will be experiencing the world of Halo as a recruit!