I know that this has been said before, but I want it to be said again until the devs introduce it. You know how War Thunder adds back the Maus every year to research? What if the same was the case in Enlisted; every November sale (or May sale or Summer sale) the devs add back every pre-merge squad and weapon to research, and a single point suffices to keep it unlocked. It's obviously at the end of the TT and you have to have either the whole TT unlocked or 6 things in BR V. You can unlock it during one or two weeks.
This is decidedly different from the loot box suggestions, but I am open for a "returning campaign" thing where you can research special squads and weapons too. So, what do y'all think? Do you want these weapons and squads to return?