Wow really? Since when/what version? I have to see it. How did they solve the serialization issue? If I remember correctly that was necessary to pass objects between threads.
I think they became stable in v12. I'm actually not sure about the internal implementation, but from user's point of view you can pass almost [1] any value via a message and you will get a copy on the other side. You can even share memory between threads with SharedArrayBuffer.
