It is a quote from the article, hence why it is italics. How is this unsubstantive? It's the last lines of the article, it practically answers the title question. It's satire and a polemic.
Not even slightly. The definition of substantive:
having a firm basis in reality and therefore important
Quotes, citations, showing one's work are all inherently substantive.
To take something seriously as Nazism in the context of a game like a puzzle to be solved, it's brilliant and absurd, and literary cleverness, and worth repeating as is. And this wedge fits within the timing of the article, itself wedged between rampant Nazism in the U.S. but before the U.S. had entered WWII. I doubt this activity could be called a game during or after the war, no matter the satirical hints.
Adding no information? That's the vast majority of comments on HN including my own, which don't get either an up or down. But fine, you can say it did not enrich the conversation.