> Consider an outage email containing a diagnostic report

So, here's the problem, I don't care. I left the company. I cannot access the account anymore. The project is dead. There are a million reasons why I just don't want your emails so there's no excuse to not add an unsubscribe link.

The only messages that don't have to include such link are those that if missed/ignored lead to fees, fines, death, imprisonment and other real-life consequences.

An update to your privacy policy does not fall into that category.