I've found documentation that solved this for me. In case anyone else has the same question, it was here:
https://wyday.com/wybuild/help/faq.php#in_client_wyc
Rebuild wyUpdate every new versionEverytime you create a new version, rebuild wyUpdate and include the newest "client.wyc" and wyUpdate.exe in your installer.
You should not include wyUpdate.exe in your updates wyUpdate self-updates. The client.wyc file, however, can be included with your updates (especially if you change any of the fields listed above).
Thanks