Nice work, thank you.
I had to change the code like this so it could work:
//Get the order ID of processing orders
  $order_ids = $wpdb->get_results( $wpdb->prepare("SELECT ID FROM {$wpdb->prefix}wc_orders where status = %s or status = %s;", 'wc-on-hold', 'wc-processing' ));

Could you add Variation SKU? At the moment, only Single Product SKUs are shown.
And actual stock level would be nice, also.