Please branch and build google-roboto-slab-fonts in epel8 and epel9. If you do not wish to maintain google-roboto-slab-fonts in epel8 and epel9, or do not think you will be able to do this in a timely manner, the EPEL Packagers SIG would be happy to be a co-maintainer of the package; please add the epel-packagers-sig group through https://src.fedoraproject.org/rpms/google-roboto-slab-fonts/addgroup and grant it commit access, or collaborator access on epel* branches.
I don't understand why you think this package is not available in RHEL8 and RHEL9? I see this https://gitlab.com/redhat/centos-stream/rpms/google-roboto-slab-fonts another proof, if I still tries to request epel branch then I get this message ~/fedgit/google-roboto-slab-fonts$ fedpkg request-branch epel9 Could not execute request_branch: This package is already an EL package, therefore it cannot be in EPEL. If this is a mistake or you have an exception, please contact the Release Engineering team.
Oh you're totally right, looks like this is shipped in PowerTools for C8 and AppStream for C9. Sorry for the noise.