Great question & congratulations on the upcoming launch! The answer depends on whether or not you were using Shopify Payments, and if Shopify Payments was in "test" mode when processing the orders. If test mode was enabled, the delete option should appear once the order is cancelled; however, if you processed real transactions, then these orders can not be deleted and would remain in your admin.
Are there any roadblocks you're facing while preparing for your launch?
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