Edit order before approval

Also how to edit the text that appear in the woocommerce front?

Like “pre order, Order waiting for approval, …. and other text strings related to the plugin”

function so_39193164_is_editable( $editable, $order ) {
    if( $order->get_status() == 'waiting' ){
        $editable = true;
    }
    return $editable;
}
add_filter( 'wc_order_is_editable', 'so_39193164_is_editable', 10, 2 );

use above code for making an order editable before approval.

For changing text like pre-order goto Woocommerce-> Settings->payments->Woocommerce Order Approval manage.

Also you can edit text using translation plugin like loco translate.