I assumed this was already the case but regardless this is a great change!
I hope more developers get their apps verified. It boggles my mind that the Steam flatpak isn't verified, for example (even more bizarre is that Valve encourage people to use the Steam flatpak despite it being unofficial!)
Hopefully the Flathub website, Gnome, Cinnamon, and now Plasma showing verified app status will be the kick up the arse devs need.
Yeah I get that SteamOS wouldn't, but Valve themselves have explicitly stated people should use Flatpaks, not distro repos or Snaps (perhaps with an exception for Arch repos if what you say is correct).