More or less, yes. Visual consistency is very important, as is some sort of continuity in the mechanics. As I wrote in this post from a couple of years ago "Lack of visual consistency helps to break immersion. Making sure things stay looking the same helps ground the universe and tie it together instead of letting it look like a mishmash of loosely-connected but otherwise separate continuities. Changes to the design of something — a character, species, ship, weapon — need a damn good explanation. Star Wars and Star Trek do a much better job of maintaining visual consistency than Halo has typically done."

The AR, BR, pistol, SPNKr, Needler, and other assets have iconic designs. Slight remodels are fine so long as they are readily identifiable as that classic item or weapon. Bungie managed an overall greater degree of visual continuity, though they did redesign things noticeably on occasion. Still, most assets retained very similar profiles, alien physiologies (except the Brutes) were highly consistent. Even the Chief's armor remained nearly identical from Halo 2 to Halo 3, because it was supposed to be the exact same suit of armor.

If something is going to be redesigned, it needs to be evolutionary. In other words, it should exhibit some sort of clear design lineage with its previous counter parts. Also, it needs a damn good explanation. That's why the explanations for the new designs for the Chief's armor or Grunt & Jackal physiology are lacking. We don't even have explanations for the redesign of the Dawn, or why the plasma rifle was given a profile similar to the carbine, or why the rocket launcher is a single-tube model now. The classic SPNKr was an iconic design. No other rocket launcher in any other game series looked quite like it, much like how the rest of Halo's weapons looked quite unique and distinct. Some were also quite distinct in terms of gameplay, particularly Covenant weapons like the Needler. Incidentally, it appears that this new rocket launcher is functionally the same as the classic SPNKr, as after reviewing gameplay footage the two brief shots of it reveal that it has a two-round magazine. Where it keeps that second rocket is anyone's guess. So, what reason did 343i have for redesigning the rocket launcher? It wasn't for game balance, as it still fires two shots before having to reload and it wasn't necessary for smart-scope as the AR & sniper show. Like every other radical redesign under 343i's watch, it appears to have been changed for the sake of change, to let some artists or other personnel flex their creative muscles without having to respect what came before, and whoever was responsible for the rocket launcher decided that it shouldn't look unique or distinctive and should look more like a generic SMAW or AT4-style design.

So what's next on the chopping block? Will the AR be redesigned to look to look more like this Advanced Warfare AR:

Or will the sniper rifle be given a more "normal" looking optical scope and given a far different profile, like this fanart here:

Or will the plasma pistol and needler be thrown out because they're not conducive to the whims of some artist and/or because some pro gamer didn't think it was e-sporty enough? Where does it end? Fortunately, it seems that a worst-case scenario of Halo metamorphosing into something barely recognizable as Halo won't happen soon, because 343i doesn't seem to have any goal or direction. Most Covenant weapons and vehicles retained the same designs they had in Reach, probably because the same guy moved from Bungie to 343i; only the ones that weren't present in Reach (e.g., the beam rifle & carbine) were redesigned, but at least keep a similar profile. The BR, AR, and other old UNSC weapons have similar profiles to their old models as well in Halo 4; even the Halo 5 SMG still retains a similar profile to previous models despite some noticeable changes (the magazine was moved from the left side to a slot on top). H2A, like HCEA, reused old assets from Halo 3 & Reach, and any models that had to be created from scratch look damn faithful to their Halo 2 versions (though Saber is probably responsible for that). But then you have the people responsible for the Chief's new armor, the redesign of the Dawn, the new Jackals and Grunts, the Storm rifle, and this new rocket launcher. It's like a madhouse there. There's no singular vision, no goal, just a bunch of people given carte blanche to do what the fuck ever. It wouldn't surprise me if 343i's art department has a banner that says "Keep things faithful or show no respect for previous designs. We don't care either way!"

Personally, I'd like better visual consistency in Halo. Star Wars and Star Trek do much better jobs in this regard despite being much older franchises with more content.

P.S.: If you want to see how every model of weapon stacks up against their predecessors, well, here you go: