My 2 cents
SDWAN is not a replacement for MPLS. In my humble point of view SDWAN
- Will keep the architecture simple (i.e. whether you have MPLS or internet or migrating from one to another, basically SDWAN will keep the architecture simple and scalable as it will build tunnel over whichever service you choose).
- Will not need to exchange your LAN routes with your ISP (simplify operation).
- Will expand easily to public cloud services (like AWS, Azure, GCP, Alibaba) - Scalable again.
- Will secure your internet access as the SDWAN appliance is also a UTM.
- Will also allow you to easily integrate with cloud security services (like Umbrella) as SDWAN is step one of SASE deployment.