The funny thing is that many sites today will serve their static assets via CDN so the article is basically saying switch from one CDN to another.
Yes it is...? Google Fonts is the service, not the fonts themselves. Check the "About" and "License" tab of any font on Google Fonts, they're not created by Google.
From the article: "then you’re best off downloading your used Google Fonts and self-host them"
I read that as "use Google Fonts"?
Google Fonts is also a website which is used by many to search for and compare fonts. The site conveniently packages font files together and provides a "Download" button. I've always thought of this website as "Google Fonts" and have always downloaded and self-hosted fonts.