Ah, that's a very fine point. The rpmfusion RPM isn't officially supported by Valve either.
Edit: Valve releases tarballs and a .deb package. Why would they release a .deb when Arch (which steamos is based on) doesn't use .deb? Releasing a .deb makes me think they test the thing on Ubuntu or Debian
I’d still take an unofficial wrapper over that time Steam was wiping home directories.