I just noticed this change today, when I was looking for Armbian USB screen framebuffer driver, and was lead to https://gist.github.com/colindean/3d206b6ca1fe4349bc86
Upon hitting the link, Github demanded a login to the site. Previously, this would immediately display the contents of said gist - only if you wanted to make write changes did it ask for credentials.
Is this one of the new Microsoft-ownership based changes? What other changes can we expect?