There is already a gathering consensus that the AR needs to be nerfed. I partially agree; the effective range is the only domain that might need tweaking. Yes, it is annoying to be descoped by the AR. Up close, it is exactly as effective as it should be, and it should outclass the BR, Commando, and Sidekick at close range. Additionally, the ADS mechanic in this game seems to be a halfway between CoD-like and Halo; it likely appeals to those who have come to expect it, but especially on the current maps, it doesn’t seem extremely necessary and should only be used in engagements where you have a significant range advantage or an ambush. Otherwise, it makes a lot more sense to hip fire, it’s plenty accurate as it is.
However.
For a majority of this flight, there was access to 3 relatively small maps - Bazaar, Recharge, and Live Fire - While access to Behemoth came later.
There are really only a handful of longer sight lines on those three core maps, usually by where those weapons spawn. It might be too early to really establish how “meta” the AR is given we’ve only played on smaller maps. If anything, on Behemoth I saw the opposite - People noting how easy it was to snipe camp. No one felt the AR was overpowered in that scenario, one it isn’t as suited for. When the majority of ALL engagements are short to mid range, wouldn’t it make sense that the AR is working well for them?
When the entire sandbox is added, (Weapons, equipment, vehicles, game modes) in addition to all of the maps, it will be easier to narrow the absolute strength of each weapon. As it stands now, the AR and Sidekick are great compliments for starting matches, and when given larger maps, the BR and Commando will rightfully edge out the AR. The arena is just as important in deciding the effectiveness of your kit.
Either way, Infinite needs to differentiate itself from previous Halo games - A pure BR meta would be nothing new (boring), and a pure AR meta wouldn’t be ideal either. Somewhere in the middle would be nice. Given that historically the AR has been pretty worthless, it makes sense 343 is making the attempt to bring it up to par with the other weapons, which might take a few more tweaks to get it perfect. In spite of that, it is pretty close and in a great place.
Tl;Dr, it might be too early for drastic balancing changes until we see the bigger picture.