WooCommerce - Disable WooCommerce default category

<?php
/*
Plugin Name: Disable WooCommerce default category
Plugin URI: https://www.willhosts.com/
Description: Disables the default category behaviour for WooCommerce v3.3.1 onwards
Version: 1.0.0
Author: WillHosts Ltd
Author URI: https://www.willhosts.com/
*/

/**
 * @author     WillHosts Ltd
 * @since      v1.0.0
 * @copyright  Copyright (c) 2018 and Onwards, WillHosts Ltd. All rights reserved.
 * @license    GPL
 * By viewing, using, or actively developing this application in any way, you are
 * henceforth bound the license agreement, and all of its changes, set forth by
 * WillHosts Ltd.
 */

// Cache default product cat option for WP_Term_Query
$default_product_cat = get_option('default_product_cat');

// Filter WP_Term_Query to exclude default category
add_action('pre_get_terms', function ($term_query) use ($default_product_cat) {
    if (in_array('product_cat', $term_query->query_vars['taxonomy'])) {
        $term_query->query_vars['exclude'][] = $default_product_cat;
    }
});

// Filter default product category option in case WooCommerce add a user option
add_filter('pre_option_default_product_cat', function () {
    return -1;
});

// Hide 'uncategorised' instruction from CMS
add_action('admin_head', function () {
    echo(
    <<<HTML
    <style type="text/css">
    .edit-tags-php.taxonomy-product_cat .edit-term-notes {
        display:none;
    }
</style>
HTML
    );
});

// Trigger 404 for product category on frontend
add_action('get_header', function () use ($default_product_cat) {
    if (is_tag($default_product_cat)) {
        status_header(404);
    }
});