If the US army wants to supply one to every soldier then they will need much more than 500K units.
Military equipment breaks all the time and it’s not because of poor build quality, it is constantly being put through the most extreme conditions possible. Conditions that are hard to imagine as a civilian.
OK, they'll need much more than 1 per soldier. But a Hololens 2 Industrial Edition costs $5k. This works out to $44k per soldier, and obviously not every soldier in the Army will get or need one.
Let's get real, this is just outrageous, typical boondoggle military spending.
While I don't necessarily disagree with the sentiment, a good chunk of the contract must be for R&D. The US Army isn't buying a ready made, commercial off-the-shelf product.