I also forgot about one thing - they upgrade and abilities will be avaible after setting Battle group HQ (like grens STg's and Panzerschrecks for Pions).
Since Volks become pretty versatile on most ranges after the MP44 upgrade, I wonder what the advantage of this unit would be and why I would waste a good doctrine for this one? So you can spam them out in order to occupy all houses like Osttruppen? In combination with the very potent Sturmpionier, who can clear some houses in the super-early game, this might actually be too good - or completely useless, hard to tell. But in general I dont see the advantage of Volkssturm over the ordinary Volksgrenadiere...