Then it should be avaliable at least on 1941 and 1942 maps yet they aren't.
Although I see no harm in making it avaliable in 1944 maps as well. Between 1943 and 1945 roughly 330 000 AVTs were made which is already good enough and I am not even considering SVTs avaliable from previous years.
Also AVT was better than the SVT. While it's main point (fully automatic fire) was a disaster it's still better than the SVT because it has thicker stock which should solve the problem of SVTs stocks being brittle and having tendences to break. It also have more effective muzzle break. It should technically be all around better gun, which might be the reason why only AVTs were made after 1942.