not sure who did/didn't follow the development cycle of this game but here's some background from a Bungie Tester
http://www.bungie.net/ga/Forum/Post/70895980/0/0
hopefully this sheds some light on why the story is so chopped and screwed.
kinda disappointed overall about this game, was really hoping for more. i think the Activision contract was the worst thing Bungie could have done because now they are at Acti's mercy. looks like the same thing happened with this as BF4... parent company knew title was incomplete and pushes launch anyway. seems to be the norm. this is the kind of stuff that makes me want to stop playing.