If you haven’t already seen it - check out the documentary “343 Industries versus the world”. It is free on Youtube and 1 hour and 20+ minutes of behind the scenes footage from the development, press interviews, pro player interviews, gameplay, and more. This is without a doubt the definitive Halo documentary video and really highlights everything that 343 have managed to do with the Halo franchise ever since they were given it after Bungie left.
I think the editors did a great job, but I really would have loved to see a bit more insight into the amazing launch of The Master Chief Collection. It really was an incredible time in the world of Halo.