No, you are likely still vulnerable if you have this versio of this library and a typical sshd instance, I believe it's about the linking rather than the init system.
Remember that the vulnerability was introduced by distributions patching sshd to talk to systemd. It doesn't make sense for a distribution to patch sshd like this unless they use systemd. Thus, choosing another init system may save you indirectly, even though you're right that this is really about the linking.
Ultimately, the attacker deemed systemd to be common enough to consider it as the way to hijack sshd, but indirect enough to avoid discovery by audit. It says something about software monoculture.
