Your titled question was answered. The discussion Forum is now an App. Let me add here, along with the website.
In answer to your rephrased question, you could have directed it to @vikicommunity who acknowledged changes being made to the forum in their posted thread. This is another reason to do a search before creating a new thread. See link, and quote below for the thread. I myself have not checked out the App in detail to know what it has, that the website doesn’t. So far it seems a replica of what’s here on the website. In the links in my first reply, others are discovering the changes just made on the website, and sharing. You may want to check those links.