Looks like they are loosing the bespoke Go fonts (https://blog.golang.org/go-fonts) and going with Work Sans and Roboto. I understand the reasoning.
Personally, I have a big soft spot in my heart for the go fonts . Whenever I feel like coding like it's 1979 again, I load them up in my editor and pretend I'm looking at well written documentation from my childhood.
[edit: Yay, Go fonts remain for source code display!]