fedora remote is now delivered via the
fedora-ostree-repos package, which allows the Fedora/Silverblue teams to deliver configuration changes via the RPM (and subsequent Silverblue composes).
fedora-workstation remote was not delivered via an RPM and was configured as part of the post-compose process. This made it difficult to deploy changes to all Silverblue users.
The main difference between the two is the configuration. The
fedora remote points at a new set of infrastructure that improves the download speeds of ostree content.
$ cat /etc/ostree/remotes.d/fedora.conf
fedora-workstation remote references the legacy infrastructure that was previously used. This config is still usable (for now), but it will likely result in slower download speeds.
$ cat /etc/ostree/remotes.d/fedora-workstation.conf