This is all sizzle no steak. Marketing without substance, frankly.

A proof-of-concept doesn't provide any value. For Linux to gain further adoption a gargantuan effort is needed to get things from 90% done (or 90% working) to fully working. Any Linux distribution is already suitable for government use. Manjaro, Fedora, Ubuntu, Debian. They're all fine distros. The only remaining problem is quality. Things don't work or suddenly stop working for no apparent reason. For government use that's a deal-breaker. It's also a deal-breaker for gamers. Which is why SteamOS has been relentlessly fixing reliability issues. So if I had to bet on a linux distro going mainstream, it would be that one.