Originally Posted by Korten
Though I will say, while the Elite designs were retconned, I do hope people understand that the armor they wore wasn't (regardless of what Forward Unto Dawn will have you believe)
Maybe hard to see, but in the background you see Elites wearing their Halo 1 - Reach armor.
Edit: And I will not get into any argument here.
You're on the right track, though. Covenant armor, weapon, and vehicle design/functionality varies from fleet to fleet. 343i has confirmed (through the visual guides) that all Covenant design variants, in every Halo game, are canon; that is, with the exception of Halo: CEA retconing the designs of Halo: CE. The armor worn by the Storm-class Sangheili of Halo 4 is specific to the colony of Hesduros (which is where Jul 'Mdama recruited the bulk of his armada), which was likely what FUD was showcasing.