This is a feature requesting an M16A1 variant for the US faction.
It would bring balance, giving the US faction full-auto capabilities to those that wish to field it. As witnessed in Grenada 1983 the M16A1 was in wide use during the 80s where Reforger takes place.
Granted, A2 was fielded by '89, but having A1 variant would give mission makers more options for early 80s missions.

EDIT 25.6.2022:
Jonathan Ferguson, a weapons expert and Keeper of Firearms & Artillery at the Royal Armouries comments time when M16A2 was first issued to US Army (1986). This would further support inclusion of an M16A1 :)
https://youtu.be/NAgyOYepCSE?t=107