I’m a certified Linux professional of over 15yrs and I have never installed Arch. Not once, never needed it. It offers nothing I can’t either build myself or just install Debian and change what I need it to be.

This is a non story but people want to hate on MS so will grasp anything they can to try and make a thing out of it.

It’s is supported but iirc you still need to actually install flatpak before you can install anything from flathub.

You’ll find the instructions on the flatpak website.