Doesn't matter. Unless you do TaskFactory.StartNew or Task.Run, it's not going to try to schedule work on another thread. Everything is happening in the main thread in your code.
I am having hard time understanding what you are trying to test here. I am worried that .NET code is not really testing what you think it is.
[1] https://msdn.microsoft.com/en-us/library/dd997402(v=vs.110)....
Maybe you mean we should schedule something which has a complete event loop? That would be a lot more fair wrt the Akka version, but the Go version does not create any threads either.