A less finnicky approach would be binding to 0.0.0.0, then configuring incoming firewall policy. By default deny, then allow SSH through wireguard network. Or by default allow then deny SSH through public network.
.. but that doesn't gain all that much tbh.if anything the only hesitation I'd have on listening to * and relying on firewall rules is if the service comes up before its configured. but exposing sshd isn't even that bad