Not only did I try, but I am playing a game with it.
It is important that you do a refresh of the unit mod file after this update.
And yes, vanilla Blue Max does show Russians, but only when you cycle the unit mod file.
There is something that forces defaults on start up, go to mods, remove units, ok, activate units, ok.
On default Blue Ax it will show Russian unit art.
After creating a copy as explained with the Allied Minor as Major_05 going through these steps will show Belgian units.
Again no speculation, but testing.
I am a little hesitant to show screenshots as I do not want to spoil the campaign by showing troop dispositions.