No idea why but @extra-add to create /var/varnish on installation does not work; it's odd anyway, so use working @sample instead. To have varnishreload(1) work out of the box, it must know where to find varnishd(1), which however listens on a random management port unless explicitly given. With these two fixed, "pkg_add varnish && rcctl restart|reload varnishd" work again without any changes in between.