i agree with that definition but then smalltalk nor any other language are using message passing for regular method calls because they are not asynchronous unless they use explicitly asynchronous methods.

Nah...IMHO message-passing is a generalization.

The point is that it encompasses all of these things: synchronous, asynchronous, local, distributed, late-bound, early bound, point-to-point, broadcast, multicast.

And ideally, you should be able to select which kind you want on a case-by-case basis. With ease.

Rather than having to choose a different programming language.