WordPress Version: 5.9
/**
* Returns all the possible statuses for a post type.
*
* @since 2.5.0
*
* @param string $type The post_type you want the statuses for. Default 'post'.
* @return string[] An array of all the statuses for the supplied post type.
*/
function get_available_post_statuses($type = 'post')
{
$stati = wp_count_posts($type);
return array_keys(get_object_vars($stati));
}