This is due to the check in sshd.py:
if DISTRIBUTION_FAMILY == SLE:
Instead of assuming that the package is called "openssh-server" on everything that isn't SLE*, we should really exit here if we don't know for certain. See nfs.py for example.
I don't have access to an OpenSuse machine right now. Instead, I've checked the code, and did a test on SLED11, by changing sshd.py before running tl-setup. Seems to work.