The systemd unit current launches:
After=network.target remote-fs.target nss-lookup.target
This doesn't guarantee that we have acquired an IP address (see: https://www.freedesktop.org/wiki/Software/systemd/NetworkTarget/).
Because of this, binding to an address using e.g. 'ListenAddress 192.168.1.12' will make sshd fail to launch if the interface hasn't acquired an IP yet.
network-online.target should probably be added to the above to positively ensure that we've acquired an IP before sshd launches.