Well… shit.
At least they confirmed they're working on enabling EAC correctly… at some point.
If that's a developer, I assume what happened is that they enabled Proton and gave it a quick test to see if it worked. It seemed to work so they made the original post.
Then a manager saw the post and said that they don't actually have CI and QA set up for it, so they can't list it as officially supported. Which... Fair, I guess.