Terminaing the non-Meraki VPN on peer on the vMX won't work based on my current experience, which is why I am asking about Azure VPN Gateway in the mix.
Right now I am using hub/spoke with my remote offices/teleworkers (MX/Z-spokes) connecting to my corporate office (MX-hub). At corporate I have a Fortigate firewall making a VPN tunnel to a 3rd party datacenter. I had do to it this way because non-meraki VPN routes are not advertised through Auto VPN and some of my spokes are dynamic IP or behind NAT devices, so I have no way to terminate the non-Meraki VPN tunnel directly to all my spokes.
Thus, all my spokes route through corporate hub then hop over to FortiGate firewall to get out that 3rd party datacenter over VPN. I'd like to eliminate having to route the spokes through corporate hub, and was thinking of vMX in Azure.