Dealing with variables with gettext function

You could just rename the labels associated with that post type.

class News_Post_Type {
    const POST_TYPE = 'post';

    public static function init() {
        $post_obj = get_post_type_object('post');
        $post_obj->labels->name = __('News Post', 'textdomain');
        $post_obj->labels->singular_name = __('News Post', 'textdomain');
        // You can continue to rename all the label properties, this is just an example
    }
}

add_action( 'init', array( 'News_Post_Type', 'init' ) );