I have been regularly pulling release notes from Github for software that I care about via api.github.com. Every few hours for the past 5 years. Github has a limit of 60 requests/hour for unauthed requests.
What I've noticed in the past 2 weeks is a steady increase in 502 errors. It looks like a straight line up and to the right.
Which is weird, because a response like that is 100% cacheable.