Story is one of them there treading water and status quo reset bores it seems. You watch the ending cutscene, you've got all you need. Cortana evil, new war, Halo lights up. (Oh and establish Locke as new buddy cop pardner because flappy-mandible Arbiter wasn't demographically exciting)
343 really took the Halo series into a boring cycle. The 3 ending and the Machine Planet were perfect lead ins to an all new take, but instead its just...'its like poetry, it RHYMES' shit. Cortana becomes new Gravemind, Guardians et al the Flood, yes well done. Flash up that John Dalberg-Acton or The Joker quote in typical white text Writer-chan. Really dot those i's.
whole story really felt like they changed everything in mid-dev. trailers and marketing makes no sense, like Bungies false Halo advertisement back then
Microsoft marketing, you have to understand, is this slow moving and myopic thing. They will set upon one concept, one thing, one phrase, and drive it all the way to the finish line. With Xbox One they thought that 'All In One' shit was so clever, they named the console after it. Took years and an entire regime change to steer that into a new direction.
With this here Halo 5, the only thing that probably made sense to the 100's of orbity marketing types was the 2 main characters and FRICTION. Trying to tell them "its also mainly about this AI slavery thing too..." is too late. They're already out the door talking amongst themselves about THE DUALITY and so forth. Hell, their visors being Blue vs Orange probably gave some guy a chubby its so 'tightly packaged'.
Marketing land is a scary place, especially in the billion dollar bracket. You may as well be trying to communicate with aliens at times.