This does not help much without doing further digging. I checked the "Steam" package and for me in Flathub I see a link to "See Details" for the publisher. Clic

This does not help much without doing further digging. I checked the "Steam" package and for me in Flathub I see a link to "See Details" for the publisher. Clicking on that takes me to the contributors page of their Flathub GitHub repo. Am I supposed to know if these are employees of the company or not? I am on mobile, so maybe there's more info on desktop? I see nothing indicating if this is official or not, other than a note at the bottom of the flathub description telling me it is not official, which seems strange for that to be the only place indicating that.