//Must be "Select Field" in "Group Fields (ACF)"

add_action( 'edited_term', 'wpse_created_term', 10, 3 );
add_action( 'delete_term', 'wpse_created_term', 10, 3 );
add_action( 'created_term', 'wpse_created_term', 10, 3 );
function wpse_created_term( $term_id, $tt_id, $taxonomy ) {
	$postID = 4576;
	$attribute_taxonomies = wc_get_attribute_taxonomies();
	$post = get_post($postID);
	$postContent = unserialize($post->post_content);
	$choices = $postContent['choices'];
	$attribute_taxonomies = arrayCastRecursive($attribute_taxonomies);
	$newAttributes = array();
	foreach($attribute_taxonomies as $attribute_taxonomie)
	{
		$isExist = false;
		foreach ($choices as $key => $choice) {
			if($attribute_taxonomie['attribute_name'] == $key)
			{
				$isExist = true;
				$newAttributes[$key] = $attribute_taxonomie['attribute_label'];
				break;
			}
		}
		if(!$isExist)
		{
			$newAttributes[$attribute_taxonomie['attribute_name']] = $attribute_taxonomie['attribute_label'];
		}
	}
	$postContent['choices'] = $newAttributes;
	$my_post = array( 'ID' => $postID, 'post_content' => serialize($postContent), );
	wp_update_post( $my_post );
}