So this is probably a stupid question to ask but i’ll say it anyway. So since The GRD helmet is not on the Reach disc, could it be on the Anniversary disc?
Thanks 
No, no new armor came with HCEA.
The multiplayer is all Reach, so if it’s not in Reach you can’t use it. Besides if it was only on the Anniversary disk how would you play Reach as the armour is your multiplayer armour and unlocking it from CEA but not in Reach would mess it up as they use the same armour.