I have some experience with AR-15 lowers and I would have to say that if the dimensions are the same as an AR-15 lower then the BATF probably has a pretty good case. It almost looks like you could switch out the airsoft upper for a real upper and have a functioning firearm.
Except that there is an electric motor in the lower, to power the pellets, and they have no hammer other mechanism for setting off a live round.
So no, it wouldn't work.