Have you even read the MA AWB? It says:
''Assault weapon'', shall have the same meaning as a semiautomatic assault weapon as defined in the federal Public Safety and Recreational Firearms Use Protection Act, 18 U.S.C. section 921(a)(30) as appearing in such section on September 13, 1994, and shall include, but not be limited to, any of the weapons, or copies or duplicates of the weapons, of any caliber, known as: (i) Avtomat Kalashnikov (AK) (all models); (ii) Action Arms Israeli Military Industries UZI and Galil; (iii) Beretta Ar70 (SC–70); (iv) Colt AR–15;
As you can see, it enumerates ALL AK models as assault weapons, whereas only Colt ARs are banned. That’s why you can have non-Colt AR-15s that aren’t copies or duplicates, but the same is not true for AKs.