Thank you for your input @vipulsoni
This is also documented in the Esri technical support article I reference above:
https://support.esri.com/en/technical-article/000012610
Error: The server is not ready for publishing. Please check if the Publishing Tools on the server are started
"Restart ArcMap and republish the MXD.
In some instances for this recurring issue, restart ArcMap, load the MXD, and republish the service."