Personally speaking, I'd like to see those weapons in the game. Even if I feel like this will never really happen.
Mind you, I am just another random person on the internet who most likely knows not a whole lot about weapons, and finds them appealing only on the look (except some that are universally approved as bad). I will try my best to list weapons that are still in use though. And I also am not a video game developper, so I do not know how to put those in terms of gameplay value. But hell, I am posting this just for fun in the end.
The OTs-38 Stetchkin
(I intended to post some pictures, but I could find no high quality copyright-free images. M'sorry !)
The OTs-38 Stechkin is a 5-shot, double-action revolver, in production and service since 2002, chambered in the silent 7.62×42mm SP-4 cartridge.
The OTs-33 Pernach
The OTs-33 Pernach (ОЦ-33 Пернач, Russian for "multivaned mace, pernach") is a Russian 9x18 Makarov machine pistol, derived from the 5.45 mm OTs-23 Drotik machine pistol.
Yes, this one isn't in use anymore... but it looks so nice, and is rather recent, I figured I should still post it. At least, you know this one now. And I hope you'll remember it.
The Jericho 941
The Jericho 941 is a double-action/single-action semi-automatic pistol developed by Israel Military Industries (now: Israel Weapon Industries) that was launched in 1990.
The 9A-91 Avtomat
The 9A-91 is a carbine assault rifle currently in use with Russian police forces. It was designed to be a cheaper and more versatile alternative to the SR-3 "Vikhr".
I thought about the AS Val first, but since this one got an integrated suppressor, it wouldn't have been fair compared to other ARs present in the game.
The Daewoo Telecom K7
The Daewoo Telecom K7 is a 9×19mm Parabellum submachine gun with an integral suppressor used by the Republic of Korea Armed Forces. It is based on the Daewoo K1A submachine gun, but is simplified by utilizing a blowback action rather than the gas impingement system of its parent firearm.
I wanted to put a bit more in there, but felt like it would be too much.
On a side note, while the game is set in the future, I can understand it's surprising to find weapons such as the AK47, the Dragunov or even the M1911 (TAC-OPS) in there. But all of those firearms are still in use today, and got multiple versions derived from them.
Plus, do we need to take this game's set on a serious tone ? Sure, it could bother some people's mind, but it isn't a game breaking point. It won't stop people from actually having fun. The weapons are still represented accurately, and avoid minor details that might ruin the gameplay. Thus we should still avoid weaponry that doesn't fit in the 21st century, or at least don't put too much of it, no offense intended.