Not only is Erlang's and Haskell's threading model unlike async/await, but Erlang's threading model is unlike Haskell's. So I'm just not sure what you're taking about.
I meant the coding style, not the threading model. Like the author talks about, one of the nice things about the threaded languages is that you basically just write normal, synchronous looking code and get asynchronous results. async/await lets you do basically the same thing.