Why cannot we send a feedback request for old orders?

The Google Customer Reviews program policy is such that Google can only send the feedback survey to customers who have agreed to participate in the program. Moreover, Google sends this request for participation only at the time of the order confirmation. This is the principle of the program set up by Google and we do not have any power to change the regulation. This is therefore impossible to ask Google to send this request at another moment and so to collect reviews on orders placed before installing the module on your shop.