The "other side" is completely relevant. We don't yet know if this is a policy issue, a tech issue, a legal issue, a national security issue, an account takeover / hacking, etc.
It doesn't matter because clearly support has failed. There is no way a thing like a prominent github account like this one should be suspended without immediate communication with the user, which did not happen. The fact that this ends up on HN at all is the problem.
> should be suspended without immediate communication with the user
I don't think we have enough information to definitively prove that his email address is still accurate on the account. If the account was taken over by a malicious user (hopefully not because they claim MFA was enabled), then the new user's email address may be the one that was notified.