You're right, they are different.
defconwarningsystem is showing a Yesen-class submarine and CNN article is showing a Kilo-class submarine.
A few points to think about, aside from the glaring typo for the original launch date:
The "most advanced" submarine Kazan (Severodvinsk-class) will not be delivered to the Russian northern fleet until 2019 according to this article.
The article is a copy of a blog post from nationalinterest.org on 29 September 2018, so it is still quite recent.
https://nationalinterest.org/blog/buzz/russias-most-advanced-and-stealthly-nuclear-submarine-ever-just-went-sea-32217
The article says that the U.S. made a copy of the older Yesen-class submarine from "unclassified data" in 2014 and the newer Severodvinsk-class is based on the older Yesen-class design.
"How do you start a WAR?"