I boot up #NetBSD from the install image, and it has sshd, Postfix, and inetd running before I even get to set the superuser password. Fortunately, by default it's only listening on the SSH port, on both TCP/IP v4 and v6.
But given the amount of SSH attempts per second one has to fend off nowadays, and given that whether sshd is running is a configurable option in sysinst, it's a bit off that sshd is on until the installer turns it off, or one manually turns it off.
It's not even as if it's arguably useful at that point. The only non-service account in the account database at the time is root, and root login over SSH is disabled.
The same goes for inetd and Postfix. Those seem like something that should be off at first until the installer/administrator turns them on, too.
This is an operating system bootstrapped from an installation DASD, which hasn't done any installing at all yet. It has no business delivering mail or being ready for TELNET or finger.