Introduction to the Twenty Nineteen Theme (Theming for Gutenberg)

WordPress 5.0 is just around the corner, and many of us feel excited and worried at the same time. Gutenberg brings a great change in how we use WordPress, and there is definitely some concern regarding what will happen to our websites if we should update our installations without previously testing it. But don’t worry, we have a post about how to disable the Gutenberg WordPress Editor (even if it’s just temporarily) in order to prevent unsupported themes and plugins from breaking our websites. You may be surprised to know that we are already using WordPress 5.0. Actually, we are! As Matt stated on Make WordPress blog:
If we keep the 5.0 release to strictly 4.9.8 + Gutenberg, we will have a release that is both major and a non-event in terms of new code. It’s all battle-tested. In some ways, 5.0 is already de facto out in the wild, with some forward-looking hosts already installing and activating Gutenberg for new installs.
This means that we already have WordPress 5.0 running on our servers: it’s just WordPress 4.9.8, with Gutenberg in the core. Actually, that’s not all, because WordPress 5.0 comes with an additional entry, which is the brand new Twenty
Source: https://managewp.org/articles/18052/introduction-to-the-twenty-nineteen-theme-theming-for-gutenberg

source https://williechiu40.wordpress.com/2018/11/02/introduction-to-the-twenty-nineteen-theme-theming-for-gutenberg/