Neither the title nor the article are painting it as an AWS issue, but as a websocket issue, because the protocol implicitly requires all transferred data to be copied multiple times.
I disagree. Like @turtlebits, I was waiting for the part of the story where websocket connections between their AWS resources somehow got billed at Amazon's internet data egress rates.
Only for people that just read headlines and make technical decisions based on them. Are we catering to them now? The title is factual and straightforward.