I'll respectfully disagree with you on this. SD-WAN simply means software defined, which leaves it open to a broad interpretation of what that means in practice. In a nutshell, SD-WAN refers to network connectivity that is controlled and managed via a software abstraction layer. There is no definition of SD-WAN that says it is only for site-to-site VPN.
Regardless, I appreciate the clarification as it relates to the original question i.e. that VoIP would not work correctly in my scenario 👍