MX's can't have different licensed within the same organisation. They must all have the same license type
Edit: Looks like they can have different licensed in some scenarios. In which case yes, AutoVPN can work between differently licensed MX's as the feature is supported on both advanced and SD-WAN Plus licenses.
"Can we mix two license types in a single organization?
MX licensing can now support mixed licensing with Per Device SDW+ licenses. For instance, if you have 25 MX networks in your organization, you can have 20 MX devices with Advance Security features and upgrade 5 MX devices with Per Device SD-WAN Plus licenses to get SD-WAN features.
However, the above is not supported with the Enterprise licenses. Enterprise licensed customers cannot be in a mixed license environment. "
https://documentation.meraki.com/General_Administration/Licensing/Meraki_MX_Security_and_SD-WAN_Lice...