@danluu This topic gained attraction on the ycombinator board, and it seems that github staff claim responsability for inserting "tips" into the PR descriptions: https://news.ycombinator.com/item?id=47573233 .

@danluu Tweaking the github query string I found 1.5M pull requests containing a copilot ad of some form: https://github.com/search?q=%22START+COPILOT+CODING+AGENT+TIPS%22&type=pullrequests .