Halo 5: Guardians will not include armour abilities.
I know a lot of Halo fans do not like the direction the series has been taking lately. Well, I have good news for you. A NeoGaf commentor compained about Armour Abilities making a return under the new name "Spartan Abilities", and Frank O'Connor replied "They aren't. The wording is confusing but it means. "features". Using h2 as an example, new features would have been dual wielding and boarding".
This was further clarified on Twitter by Brad Welch (who is design director at 343, in case you don't know who he is like I didn't) , who said "Arena means what you'd expect - competitive focus, level playing field, map control. Spartan abilities are player mechanics not loadout AAs."
So what do you think this means? "level playing field" and "map control" could be taken to indicate that random drops and loadouts are also a thing of the past, which I'm sure will make quite a few fans happy. Now all we need is some information on the Campaign and everything will be perfect!