So what are the other attributes that would make it DD?
According to the ATF*, the things they look at when determining "sporting" vs. "nonsporting" are:
1) folding/telescoping/collapsible stocks
2) bayonet lugs
3) flash suppressors
4) 5+ round magazine or a drum magazine
5) grenade launcher mount
6) integrated rail system (other than on top of receiver or barrel)
7) light enhancing devices
8) excessive weight
9) excessive bulk
10) forward pistol grip or other protruding grip.
Now, keep in mind that US Law** says that shotguns are essentially DDs UNLESS they meet sporting purpose tests as described above. It is true that the ATF hasn't really done squat with this, but the regulatory authority is there and they have done it in the past with the Striker 12 and the USAS 12. So while there's no shortage of those of us with 870 Tacticals and converted (but 922r compliant) Saiga 12s, a stroke of a regulatory pen can mean we're filling out Form 4s and getting fingerprinted for the tax stamps.
Faced with that, I just don't see them bothering trying to make a semiauto AA-12 for civilian sale; that's an investment of real money that can be negated pretty quickly. Whatever happens to the regulatory environment, the AA-12 was designed quite some time ago, and if they were remotely interested in making one for civilians, they could have done so long before now. My guess is that they won't, possibly because of this regulatory possibility.
*As found on page 5 in their
self study on importability of certain shotguns. While the publication is indeed dealing with imported guns, the criteria are used for everything.
**
US Code Title 18, Section 921(a)4(B).