Redirect to Multisite site 2 if site 1 has a setting

If you are implementing a global functionality for your entire multisite/sub-sites like what you describe, you should implement this as mu-plugins instead adding the cuztomization inside a theme file, just create a file like in wp-content/mu-plugins/GlobalConfig.php which holds the customization you want and will take effect globally, unless you want this customization for only specific sub-site.

the init runs before the wp_loaded, but you can intercept the request at plugins_loaded hook since it runs even before init


add_action('plugins_loaded', function() {

    //skip wp back-end request
    if ( is_admin() )
    $isDeleted = get_blog_option(get_current_blog_id(), 'deleted');
    if ( $isDeleted )
        exit( wp_redirect( '', 301 ) );