I thought the over representation largely went away with the all volunteer forces.
My understanding was that blacks were slightly over-represented in the Army during Vietnam era, but slightly under-represented in the combat arms.
It did, at least those who die seem to be white and/or mostly Hispanic from what I can tell, according to pictures of the men.
The over representation is in support units, not in combat deaths, even in the Vietnam war, the black male age group was just barely under represented.
In Special Operations, they account for only about 1.5%, and when the San Diego Union did their report on that, it was across the board, all Special Ops units, all branches.
I understood the group that has always been over-represented in the US military was Southern whites of Scotch-Irish ancestry.
I have no idea if that is true.