WooCommerce - Removes all product types from product type dropdown select except "simple product"
add_filter( 'product_type_selector' , 'woo_custom_product_type_selector' );
/**
* Removes all product types from product type dropdown select
* except "simple product"
*
* @access public
* @since 1.0
* @return void
*/
function woo_custom_product_type_selector() {
$product_type_selector = array(
'simple' => __( 'Simple product', 'woocommerce' ),
);
return $product_type_selector;
}