I am sorry, but what? What is your source? From a new account[1] with only 3 comments overwhelmingly favoring yarn over npm it's difficult to trust this as it just seems like SPAM. I have been developing in Node over 3 years and trying new things constantly and no, I'm not really excited about yarn. Nor many Node developers I know.
[1] https://news.ycombinator.com/threads?id=terink