No, but reality is that military has, throughout human history, been a driver of new technologies.
If military is embracing linux as essentially client/desktop OS, it's a good thing for those who want linux as a viable desktop alternative, and some technological inventions and innovations are likely to find their way into civilian use soon enough.
And in the end, it wouldn't really matter for those killed if they were killed by a ship running linux, windows or macOS, like it doesn't matter to them if the ships are built of steel or carbon fiber, like it doesn't matter to them if missiles use solid or liquid fuel and so on. Because in the end, it's people that kill people. Tools are innocent.