If that's the canon reason, then why are the spartans wearing the armor in the flashback during the prologue? I believe that 343 is trying to pull wool over our eyes and make us believe that this is the armor that he's always worn, all the way back before Halo: CE. They kind of wrote themselves into a corner with this, and ticked a lot of people off.
Not before CE. That was Mk. V armor, and neither Bungie nor 343i have ever said otherwise on that point. Between CE and Halo 2 Chief upgraded to the Mk. VI armor, presumably being issued the new suit after returning to Earth and prior to the celebration that was set to take place at the beginning of Halo 2 and then interrupted by the arrival of the Covenant.
However, you are partially right, 343i has indeed claimed that what Chief is wearing in Halo 4 is still the same armor he wore in Halo 3 (Mk. VI), it has simply been reimagined and interpreted by the new visual art staff. This is the first game done by a new team on an old franchise. Things are going to look different. Things are going to sound different. Quite honestly a great many of us would be rather miffed if after 4 other games (3, ODST, Wars, and Reach) on this console they couldn't offer something graphically better than what Bungie had at the beginning of Halo's Xbox 360 reign (over 5 years ago). Technology has changed immensely in those 5 years, and developers' ability to make use of what's available has likewise grown. If Halo 4 Chief still had the same cartonishly plastic-looking armor that he had back then, this thread would be ranting about how utterly lazy these people are for not finding ways to improve the graphics and appearance of this game. 343i went back and rebuilt everything from the ground up. Sounds, visuals, enemies (I've noticed not many people, if any, are ranting about the newly snub-nosed Jackals), everything has been scrapped and made new because 343i did not want to simply piggy-back off Bungie's work. They wanted to make this game as completely their own as possible. Obviously there were lements they could not get rid of. I don't think anyone would be happy if there were no Covenant, Forerunners, Assault Rifles, DMRs, Scorpion Tanks, or any of the other elements we've come to be familiar with. So rather than scrap those, they simply redesigned them. Chief's armor is bulkier, beefier. He looks like a walking tank now. But that change is also reflected in the vehicles and weapons, as they now also look, feel, and sound so much bigger and more powerful than before (although admittedly, the Warthog engine does sound a bit more wimpy this time around).
Some people are just tall, and the Chief TOWERS over the Spartan 4's, so I figured they were less than Spartan 3's in medical aug.
The IVs were all augmented, but you have to figure at this point they've had maybe 4 years for their bodies to adjust to the augmentation (if they were augmented very close to the end of Halo 3), and they were all augmented as adults. The Chief has what, 30, 40 years? I forget how old he's supposed to be. And he was augmented as a child, and a child's body (as Halsey hints at during the Ops cenematics) is far more receptive and suseptible to the augmentations. Think of it this way, if you excercise rigorously every day for the next four years, you're going to be larger and more well-muscled than the average person, or even someone who excercises three times a week. But if you were to stand beside someone who's stuck to that same regimen for decades and started when they were very young, you would suddenly look rather small in comparison. Because the IVs were augmented as adults, it is doubtful they would ever achieve the same level as John, simply because their bodies do not have the ability to adjust the way his did.
As for Cortana's firmware comment that several of you have mentioned (and some have explained), firmware is essentially the permanent programming in a computer system. Basically firmware is what makes a group of linked electronic components (hardware) actually become a computer. It is the brain, so to speak, of the system. I assume we are all familiar with software (iTunes, Photoshop, Pepakura Designer, etc.), which would be the simplest level, and operating systems (Windows, Apple, Android, etc.) which would be the next and more complex tier. Firmware is above that. Without firmware, software and operating systems are useless. Firmware is what allows the Chief to use or even have a HUD. It would also govern his shield systems as well as his ability to make use of enhancement modules (armor abilities). As some of you may recall when the Chief kills a cloaked Elite Cortana tells him to examine the Active Camo module he dropped, and them makes a comment about writing a patch to his suit's systems (OS or Software, take your pick) to allow him to actually use the module (much as you have to use an installation disc to install the proper drivers and programs before you can use a webcam, printer, or other peripheral on your ocmputer).
The long and short of all that is no, Cortana saying she upgraded Chief's firmware has absolutely nothing to do with how his armor looks.
First off, not meaning to be a jerk about it, but it's not "your" baby. It's Bungie's. They're the ones that brought it into the world. You're just the crazy/creepy uncle who's been playing with it incessantly for the last decade. And Bungie handed over all rights and whatnot of
their baby to 343i. It is now 343i's baby. Still not yours. What they do with it is what they do with it. Disney now owns the rights to make Star Wars movies. If they want to make Jar Jar Binks the central focus of the new trilogy, that's their choice, and you still have no say in the matter. It's not yours. They just let you play with it if you choose to.
Also, can someone teach this guy a new word besides "sucks?" I get it, you don't like the direction in which this first game 343i has ever done went. That goes with the territory of first games, especially when it's a new team working with something that has been established already. Someone made a Transformers analogy. I grew up with the original Gen 1 Transformers back in the 80s. Seeing Bumblebee as a Camaro I must admit ticked me off to no end. But that's the direction they wanted to take it in. The movie had absolutely nothing in common with the original Transformers except character names, but for what it was, it was still a good movie. I can sit around and whine all day about how Ironhide is supposed to be a red minivan or how Optimus Prime NEVER had a flamed-out paint job, or I can choose to simply accept that this is a new generation with a new team at the helm and things WILL be different. LEt's face it, if things don't change, they become stale, stagnant, dull, boring. These are not words a developer wants to ever have their work described as. Stale, stagnant, dull, and boring won't sell. It won't make a return on their investments of time and money. It won't please the fans. It won't give anyone a reason to come back.
Finally I say to ALL thepeople complaining about what Chief's armor looks like in Halo 4: you'd best buckle up, or punch out, because Chief's de-armoring in that final cutscene has the bearing of a decommisioning as upposed to simply changing into "casual" attire. So most likely Halo 5 WILL have what will be in essence "Mk. VII" armor, as it seems extremely likely that Chief will be getting new duds, considering what he's wearing is quite obsolete after spending 4 years adrift.