I would hope we didn't see it in our military. Every Marine is a rifleman 1st. Let's face it, those 18-year-old eyes can use iron sights just fine. Always have. Those 'new' sight planes will cause more trouble than it will fix. I.E- a solution to a non-existent problem.
There's a lot more going on in that device than just an aiming reticle. Read the whole article.
I would worry about how easy it is to jam the communications on that thing. Blue Tooth comm link? Sounds like it wouldn't take much effort to interrupt the signal path to and from those things.