Well, if that was the case they would have used a local designation for it like AR-112 or M-112, and the AK-112 is 5mm, not 5.56x45mm (.223)
Don't take this the wrong way, not trying to have a go at you or lure you into any trap, but the reason why they did it is because they obviously don't have a clue about weapons and are probably too lazy to research facts.
Take this statement for instance:
1989A1 NATO Assault Rifle: The M1989A1 is big brother to the original M16A1. It was
rechambered to accept the same 7.62mm ammo that the AK series of rifles uses so troops could use captured Soviet ammo. Although assault rifle users greatly preferred the American ammo for its damage capabilities.
Ok, Russian intermediate ammo is 7.62x39mm the last is the legth of the case; NATO ammo is 7.62x51mm.
So assuming they made an adjustable chamber so the rifle can fire both rounds:
1- the NATO round is much more powerful than a 7.62x39mm; if the rifle was made from an AK design then it would be a gas operated weapon (uses a piston that moves the bolt carrier when the escaping gases of a fired round are tapped from the barrel to push on it) the force generated by the gases of a NATO round would be stronger, if you fired it from an AK barrel, the pressure would be excessive for the piston, or if it was optimised to fire NATO, then the 7.62x39mm would not generate enough force to push the piston and complete the firing cycle.
2- the projectiles are not equal in weight or size, (7.62x39mm projectile is a bit longer), and would probably use different rifling twist to optimise the bullet spin so a different barrel may be required.
3- 7.62x39mm AKs have been replaced with 5.45x39mm AK-74 models in the russian army as far as I know; 7.62x39mm models are still used but mostly by other former Warsaw Pact and African/Middle Eastern nations.
EDIT: Oops, I think I misread that statement leading me to think the rifle used both cartridges. Bloody sleep deprivation, please ignore 1 and 2 but 3 and its designation would definitely be different.
Just look at other AK clones built by other nations, they don't use the AK prefix.
Czech: Vz58
Hungary: AMD-65
Former Yugoslavia: M-70 and M-80
PRC: Type-56 and 81
Finland: Rk-60, 62, etc