Surely you can still get it? It's unlocked for achieving 49 achievements in the game.
Yazite
Marine - Silver
Bio
Halo: The Master Chief Collection
Forum Activity
All Badges
Feet First
Made your first hot drop into HaloWaypoint.com
Halo 5: Guardians MP Beta
Halo 5: Guardians MP Beta participant.
Statistician
View your Service Record on the web.
Enlisted
Become a member of an active Spartan Company.