Some people seem to think that it's and old build of the game, and the armor is cut. First off that's near impossible. Why make a map pack for a finished game, but base it off old code? For the map pack would not work on the current build of the game. Secondly, the dev (Certain Affinity) would not even have access to any other build. Thirdly, the building of the map pack began after release, unlike Noble. So this cannot be the answer.
So that leaves the possibility of it being hidden on the disk, or being downloaded. Before I get into this, let me say I did not code Reach in any way shape or form, so I do not know the capabilities of the engine fully. What I DO understand is general game design, and how to find things in the "code", which is really just a file directory.
In my opinion, I think the new armor is going to be in a download. And that is because I cannot find it on the disk. Now I'm sure people that disagree with me are getting ready to pull out the old "Disk Locked", or "Otto Said balh blah". Here is my rebuttal. It is called "Data Mining".
The difference between modding and data mining is that modders just set their credits to 9999999999 and boot up the game. Data mining is the act of looking the games code for things not easily seen on-game.
I did not mod my x-box to unlock everything like you may think. Oh no. I'm using a modded version of a program called "MyWarcraftStudio". This allows anyone to enter the file system of the game "World of Warcraft", and then fiddle with them as such. I used to make mods for the game, oh, 3 years ago I think, towards the end of BC. This is besides the point.
Using the program, I inserted a Reach disk, and was able to begin to browse the folders. I found folders for every piece of armor, the corresponding attachments, and armor effects. Including UA chest, Officer, Flames, and Bungie Blue Flames. I did not find anything that I could not identify. While it is not impossible I my have missed anything that is still hidden on this disk, however if I did, there is not much more to come. This leads me to why I believe the armor will be downloaded: simple fan cry out.
We begged all halo 3 long for Blood Gulch. We got it. We begged since Halo CE for pelicans. We got it, even if it is hidden. We cried to nerf the BR, and yes, we got it. And one of our biggest pleas was for new armor. Why oh why oh why would they not incorporate this into a game that they basically re-built from the ground up? Especially when the focus on a vast armory for the players is one of the main focus points of the game?
Now I'm sure a bunch of you that pulled out your other arguments are saying right now that new armor would only be used in the new maps. To think that this could not be fixed with a simple title update would be so naive that it may warrant and IQ test.
So ion short, due to me not finding it while physically scrolling through code, the large outcry for it, the simplicity and likelihood of an updated armory system, and the shear near impossibility of a new map being build off an old system, I must come to the conclusion that the most likely outcome is that the code for the new armor's visuals will be beamed to my Xbox when the pack comes out, and the code for wearing it will be beamed when I buy the maps.