At first glance it probably doesn't sound like a problem, I get it's effectively the same as serving them from Google, but I know fonts can also sometimes have strange licensing requirements… so I always figured it was safer just to avoid it entirely.
"The open source fonts in the Google Fonts catalog are published under licenses that allow you to use them on any website, whether it’s commercial or personal."
https://developers.google.com/fonts/faq
This would be the opportunity for them to tell us that applies only to fonts delivered via CDN. On the contrary, they later recommend self-hosting.
https://mobile.twitter.com/matt_lowne/status/119537351841594...
tl;dr - Kerbal Space Program YouTuber gets every video he ever made copyright claimed by Sony after using a track from YouTube's own audio library.
To their credit YouTube did offer a "solution" to the problem but they denied all knowledge of the track being available in their library.
But most of Google Fonts are either SIL Open Font or Apache Licensed
I am usually inclined to vendor dependencies on the web. Not an ideal solution but I don't like dependencies on CDNs, even if they are indeed very reliable. But apart from making sure the set has symbols for special characters you might need, it is pretty safe to do so in case of fonts and maybe even advantageous.
Also bought some fonts from other services as there are quite cheap compared to the huge amount of work going into their creation.
Downloading a font and using it on a different operating system from where the original download comes from seems to make the font look... unusual?