No. That's your valuable data so we don't prefer storing it on our side. When customer sign up for a waitlist, their record is stored in Shopify Customers section where you can do all sort of cool things with it.
You can view these waitlisted customers by navigating to app settings and then clicking on "Waitlisted Customers" tab.
You can also directly go to Shopify Customers tab and click on "Waitlisted Customers" tab.
You can then export these records in order to view their zip codes and do all sort of analysis which can help you to determine where to launch your service next.