Eye of Gnome, Media Writer, Gnome Sound Recorder and others also need to be updated.
I assume you’re saying the flatpak is out of date with respect to the version of the rpm in the repos. I’m not sure who maintaining the flatpak in the fedora repo right now. @otaylor might know. Here is a nice view of the different versions of firefox that are available where: https://apps.fedoraproject.org/packages/firefox