You're right. Something is wrong with that site today. Anyways what it says is that there is a plugin that doesn't actually null the Yoast SEO but rather it disables notifications to register the plugin. Yoast Plugin works perfectly without nulling. So here is the plugin:
Plugin that hides Yoast registration notifications
Magic Button :
Code:
https://>>>[[[Reported by Members as URL Shortener! Post the actual link!]]]<<</fSVU9f