Wait, why is Fedora making their own flatpaks? I thought the entire point is that they work on any distro and everybody gets the original source from flathub.
Just to add to the other replies you’ve got, as far as I’m aware there’s no reason why you can’t add Fedora’s flatpak repo on another distro. Why you would want to is another matter, but I think the fact that anyone can make their own repo is the fundamental strength of flatpak as opposed to snaps; it’s not tied to one organisation, Flathub is the de facto central repo but it doesn’t always have to be.
Just to add to the other replies you’ve got, as far as I’m aware there’s no reason why you can’t add Fedora’s flatpak repo on another distro. Why you would want to is another matter, but I think the fact that anyone can make their own repo is the fundamental strength of flatpak as opposed to snaps; it’s not tied to one organisation, Flathub is the de facto central repo but it doesn’t always have to be.