I think there are two things going on with this article: 

1. People can (and should) learn how to influence and persuade others through written and verbal communications
2. People can (and should) voice their opinions -- in both a timely and respectful manner

This article talks mostly about #2 above and no question it's very important. It's essential at work, at home, in the community, etc. Be authentic and be heard -- again in a timely and respectful manner.

However I've always been more of a believer in mastering #1 above. Too often people say what's on their mind and do it in such a way that is either confusing, untimely, offensive or disrespectful, wrong audience, or otherwise counter to achieving what they want to achieve. Communication and influence are essential components of leadership. And I don't just mean "convincing people to do what you want" but rather "persuading people to do what you believe is the right or necessary thing to do."

I suppose this concept of "Sciamachy" (or role-playing or shadow-boxing, whatever you want to call it) from the article can work. There are also some excellent courses online and in-person you can explore. Google "communicating up down and across the organization" for more info on that.