Assuming your actors use queues, as they traditionally would, I don't think so. You don't really need service mesh if your communication is a queue, right?

I was wondering more about orchestration of the actors... something needs to be responsible for spawning them onto machines and something needs to be responsible for tracking where they are or where their queues are. I love MSFT Orleans but I'd love even more something that fit easier into a conventional node.js and docker kind of world (C# is great but when I look at adoption curves Typescript seems to be growing fast while C# seems to be at best holding steady)

Aws step functions? That's their solution for tracking long running state.