I still have not received my Inner Chamber Emblem even after all these years.
I have played Halo: PC (yes I entered the license key for my disc on Bungie.net when that was going on), Halo 2, Halo 3, Halo 3: ODST and Halo: Reach all of which have stats recorded on Bungie.net but I still have not gotten my Inner Chamber Emblem. I even checked my Code Redemption portal and nothing. Any help would be greatly appreciated. Thanks!
Based on the playtime of your earliest character, it was December of 2014, so it looks like you didn't preorder the game or play it within the first month. I believe one of those, in addition to having played 4/6 of the previous games (at the time) was what was necessary, as it was incentive to purchase the game.