An ak has areas of design which are required for it to be considered a ak, such as the gas tube "the pipe above the barrel" the propose of it is to put the gases released from the bullet to use, pushing the slide to the rear of the gun.
Noooeeee, have you not seen the 7.62x25mm krinkov builds, they're closed-bolt blowback, no form of gas siphoning at all. Hell, they had rubber bands keeping the bolt from leaving the lower reciever due to cheap, hot-loaded, likely corrosive and/or bergan primed surplus.
It's all in the reciever, trigger and bolt setup, the VZ 58 looks exactly like an AK, and has a gas-piston, but the innards are very different.