Pushover allows per-message sound settings, so you could configure just alerts from your monitoring to play a sound and send at priority 2 which will bypass your device's quiet settings and repeat to wake you up.
On Android, Pushover is able to (optionally) play notification sounds for high-priority messages through the alarm channel like an alarm app would, so it can bypass the device's mute switch.
nobody seems to be commenting on the attack part of that post. what was the "highly sophisticated and targeted attack on our corporate infrastructure originating from China that resulted in the theft of intellectual property from Google"?
that doesn't sound like just a few end-user gmail accounts being compromised, but something that was much more serious that may have exposed more information than just what these chinese attackers were looking for.
https://pushover.net/api#sounds
https://pushover.net/api#priority2