Here's an idea, how bout for Halo 6 Chief reverts back to his halo 2 armor from Mcc. I personally think that is the best chief armor. I just say make it more modern but the same badass look or even the same. New Spartan armor just doesn't have the same feel as h2 and 3 Spartan armor.
It wouldn't fit into the cannon story. The armor upgrade (exterior) that Cortana put on Chief can't be undone. I don't see how they could implement a change of armor into the story. I like 2 and 3's armor as well but I don't see them making a change.