A simple WordPress plugin that changes the privacy policy link to point to a specific url. Perfect for theme demo sites. Just add it to your mu-plugins directory.

enable-privacy.php

<?php
/**
 * Plugin Name: Enable Privacy Link
 * Plugin URI: https://prothemedesign.com
 * Description: Enable a privacy policy link and point it to another url.
 * Author: Ben Gillbanks
 * Version: 1.0
 * Author URI: https://prothemedesign.com
 *
 * @package ptd
 */

function ptd_privacy_policy_url() {

	return 'https://prothemedesign.com/privacy-policy/';

}

add_filter( 'privacy_policy_url', 'ptd_privacy_policy_url' );