Flatpak was started by RH employee but has been developed with significant community effort.

Flatpak uses ostree, which was originally created in GNOME for GNOME OS. And GNOME has contributors not only from RH but form Endless, Collabora, Purism and others.

Flatpak can work with OCI remotes, this is what RH more interested in. And Flathub uses only ostree. OCI remotes are used in Fedora Flatpaks repacked from fedora packages with the runtime based on fedora. But who use it anyway.

Flathub itself is independent community effort. It uses org.freedesktop.Platform based runtimes which are not based on any distro.

XDG Portals are shaped by Flathub maintainers and applications developers where RH also doesn’t play significant role.

Did you mean to add a link or something to explain why you think so?

Flatpack is literally the opposite of the RHEL model that relies on vendor lock-in due to 3rd party software only supporting specific versions of a specific Linux distribution. So this might very well end up helping Flatpak, if vendors make more widely compatible Flatpaks instead of RHEL only versions from now on.

For those who don’t know, Flatpak is a RedHat offspring. It’s gonna be tough times for those developers.