I don’t think the publication date (May 8, as I type this) on the GitHub blog article is the same date this change became effective.

From a long-term, clean network I have been consistently seeing these “whoa there!” secondary rate limit errors for over a month when browsing more than 2-3 files in a repo.

My experience has been that once they’ve throttled your IP under this policy, you cannot even reach a login page to authenticate. The docs direct you to file a ticket (if you’re a paying customer, which I am) if you consistently get that error.

I was never able to file a ticket when this happened because their rate limiter also applies to one of the required backend services that the ticketing system calls from the browser. Clearly they don’t test that experience end to end.