get_posts() 可以接收描述要操作哪个post状态的参数。我会这样说：

function remove_all_kba_data(){
    //remove articles
    $articles = get_posts( 
        [ 
            \'post_type\' => \'kb_kba\', 
            \'posts_per_page\' => -1, 
            \'post_status\' => [ \'published\', \'draft\' ]
        ] 
    );
    foreach( $articles as $article ) {
        //delete post, bypass trash
        wp_delete_post( $article->ID, true);
    }
}