I'm not sure they can actually respect that 30 days absolute commitment. Let's say some internal tool flags a suspect conversation, it bubbles up and a human operator reads it and it looks like evidence of a crime. Then, that employee is legally bound in many jurisdictions to prevent the destruction of that piece of evidence.
It's one thing to commit to a "everything is deleted when you press delete" automatic policy. It's quite another to say "we'll keep some stuff for up to 30 days, look inside it for any malfeasance, then pinky promise we'll delete it".
