Halo 2 anniversary pro and epilogue?

What was the point of that, Locke’s armor was brighter and his team looked different. Arbiter’s armor was a little different and Locke had a different voice actor. Not to mention the Elites looked like the old Elites. Was there an original plan that was changed ? Or was it simply a teaser ? Whatever it was that scene set a tone that I felt was missing throughout Halo 5.

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