head.php中的Noindex页面

I have deactivated search, author, date and tag archive for my Wordpress site with this

add_action('template_redirect', 'remove_wp_archives');

function remove_wp_archives(){
    if( is_tag() || is_attachment() || is_author() || is_date()) {
        global $wp_query;
        $wp_query->set_404();
    }
}

and this

function fastwp_filter_query( $query, $error = true ) {
    if ( is_search() ) {
        $query->is_search = false;
        $query->query_vars[s] = false;
        $query->query[s] = false;

        // to error
        if ( $error == true )
            $query->is_404 = true;
    }
}

add_action( 'parse_query', 'fastwp_filter_query' );
add_filter( 'get_search_form', create_function( '$a', "return null;") );

My question: Normally I would noindex certain pages like author archive etc in my head.php for SEO purposes, but if I have deactivated it through functions, would I still need to set it to noindex in my head.php?

Check your HTML code, does it show the noindex tag on the pages that you do not want to index? Also, it's probably a better idea to use an SEO plugin to do that rather than code it yourself in template files. It helps people with no access to the filesystem understand what's going on.