On August 2nd 2018, WordPress has released Try Gutenberg Box in Dashboard, which is a new editor / replacement for classic wysiwyg editor which we are been using for long time.
It takes the blog writing to the whole new level, which has been adopted by only few folks. So, this plugin gives option to disable the dashboard notification.
We are committed to provide you peace from the ‘Gutenberg Nags’. Now you can dismiss the callout on dashboard safely.