Just adding a new commit removing those files doesn't actually remove the email address from the commit history, so it will still be visible from the GitHub web interface. We'd either have to remove the commit that introduced it in the first place (involving rewriting the history, force pushing and all the pain that that entails), or accept that the email address remains visible - which I'd think is acceptable given that it's public already, unless it's possible to hide it in Google Groups as well?
Just adding a new commit removing those files doesn't actually remove the email address from the commit history, so it will still be visible from the GitHub web interface. We'd either have to remove the commit that introduced it in the first place (involving rewriting the history, force pushing and all the pain that that entails), or accept that the email address remains visible - which I'd think is acceptable given that it's public already, unless it's possible to hide it in Google Groups as well?