In our OracleLinux9 content view we have RockyLinux9 BaseOs repository and filter that includes these packages from this repository:
subscription-manager*
dnf-plugin-subscription-manager*
python3-subscription-manager-rhsm*
python3-cloud-what*
libdnf-plugin-subscription-manager*
and then there is another filter in this content view, which excludes below packages from all repositories:
rhn-check
rhn-client-tools
rhn-setup
rhn-setup-gnome
rhnlib
rhnsd
yum-rhn-plugin
yum-plugin-ulninfo
I do not know if this is super correct but seems to work.