Kicking ntpd in rc.newwanip(v6) dates back to OpenNTPD which didn't have dynamic interface scanning support. This seems to be the source of crashes in ntpd as described in Ticket #4155, and appears to be unnecessary.
Related issues
Bug #4155: ntpd crashes on 32 bit with dynamic WAN reconnections and OpenVPN client configured
Kicking ntpd in rc.newwanip(v6) dates back to OpenNTPD which didn't have dynamic interface scanning support. This seems to be the source of crashes in ntpd as described in Ticket #4155, and appears to be unnecessary.