After upgrade to Foreman 1.15 (dev setup) I don't see vendor set for core templates - it is nil. We need to make sure during migration that all core templates has vendor set to "Foreman" (and "Katello"), so the message is shown.

        if template.vendor
          _("It is not recommended to unlock this template, as it is provided by %{vendor} and may be overwritten. Please consider cloning it instead.") %
            {:vendor => template.vendor}
        end

It is important to show this message for core templates, it's the main reason why we actually implemented template locking. Setting as 1.15 candidate.