Looks like root_hold_wait should be added to /etc/rc.d/zfs script after r355010.
If root is on NVMe and e.g. /var/db is on ZFS on top of ATA then root gets mounted and /etc/rc.d/zfs get started before ata bus scan completed. System boots with ZFS filesystems unmounted. There is root_hold_wait calls in /etc/rc.d/mountcritlocal, but zfs filesystems are not mentioned in fstab.