It might be a good idea to update the platform specific notes for redhat.
By only removing the rsa key from /etc/ssh directory does not work.
The key will be recreated on next reboot or restart of sshd.
I think that the correct solution is:
- sudo systemctl mask firstname.lastname@example.org
- sudo mv /etc/ssh/ssh_host_rsa_key /etc/ssh/ssh_host_rsa_key.disabled
- sudo systemctl restart sshd