do freebsd-update página de manual de 7.1:
Note that updates are only available if they are being built for the FreeBSD
release and architecture being used; in particular, the FreeBSD Security Team
only builds updates for releases shipped in binary form by the FreeBSD Release
Engineering Team, e.g., FreeBSD 6.1-RELEASE and FreeBSD 6.2-RC1, but not
FreeBSD 6.2-STABLE or FreeBSD 7.0-CURRENT.
parece que a resposta é "não".