Add Product Weight to WooCommerce Emails

functions.php

add_action( 'woocommerce_order_item_meta_end', 'ts_order_item_meta_end', 10, 4 );
function ts_order_item_meta_end( $item_id, $item, $order, $plain_text, $product ){
global $product;
$product = wc_get_product();
	echo $product->get_weight();
}