[Navarr]

I'm pretty sure anyone can write a github bot. I remember there used to be several (some of which would submit pull requests!)

[jaytaylor]

GitHub has not been friendly to bots in the past[1].

[1] https://news.ycombinator.com/item?id=4982240 "GitHub Says ‘No Thanks’ to Bots — Even if They’re Nice"

[yahelc]

The same bot could notify those people via email using the email address found in commits.