Get All WooCommerce Order Notes

## get-all-woocommerce-order-notes.php
<?php

/**
 * Get all approved WooCommerce order notes.
 *
 * @param  int|string $order_id The order ID.
 * @return array      $notes    The order notes, or an empty array if none.
 */
function km_get_order_notes( $order_id ) {

	remove_filter( 'comments_clauses', array( 'WC_Comments', 'exclude_order_comments' ) );

	$comments = get_comments( array(
		'post_id' => $order_id,
		'orderby' => 'comment_ID',
		'order'   => 'DESC',
		'approve' => 'approve',
		'type'    => 'order_note',
	) );

	$notes = wp_list_pluck( $comments, 'comment_content' );

	add_filter( 'comments_clauses', array( 'WC_Comments', 'exclude_order_comments' ) );

	return $notes;
}