In what world is a public email sensitive PII, mate? Sure, “never post anything on the internet ever” is the best OPSEC posture by default, but this user is a clearly-experienced self-hoster who understands the risks and consequences of what they’re doing.
It’s listed as their whois domain contact, and anyone with OSINT chops can find a long-term email tied to a custom domain with enumeration tools + breach data. Why hide it?