Revoked certificates don't generate expiry emails. Most likely, there was another certificate that shared the same domain names, which was not revoked. You can look them up on https://crt.sh/ .
However, you can change the email address on your account, which effectively re-subscribes you. Many common email services treat yourname+1@example.com the same as yourname@example.com . So if you update your email address to yourname+1@example.com , you can start getting expiry mail again. With Certbot, use:
The reminders are useful - saves me running the following from time to time, which I forget to do: sudo openssl x509 -dates -noout < /path_to_cert/cert.pem
Sure I can ignore them. But why wouldn’t I want to fix them?
The "fix" for a renewal email for a cert that you don't want any more is to ignore it (IIRC, there are only two reminders before expiration, so this isn't all that burdensome), or to completely unsubscribe your email address from all notifications. Those are the options. There are no per-cert or per-domain settings. So, no, I'm not saying ignore all the emails (though if you're getting them with any frequency, it's likely that you're using Let's Encrypt in a way in which it really wasn't designed to be used), just to ignore the emails for certs you don't want any more.