No. Flathub has nothing to do with flatpak technology itself. Flathub is just one server hosting some flatpack repos.
It's like saying .deb is Ubuntu Store. Well no, it is just one PPA among many other you could add to get your apps
It's like saying .deb is Ubuntu Store. Well no, it is just one PPA among many other you could add to get your apps
However because the official adoption is slow (very few software have official flatpak repo), flathub allowed the community to build packages themselves. But this is clearly not how it should be.
The second (more legit) reason of flathub is that small developer might not want to pay a server to host their app and flathub proposes to host their repo.