When getting pre-approved for an iPhone XR, iPhone Upgrade Program members will see a new "Add to Siri" button that can be used to record a custom phrase like "pre-order my iPhone."
Once pre-orders are available on October 19, customers can say the custom-made phrase and Siri will pull up their pre-approvals in the Apple Store app, allowing for quick order completion.
Other than the Siri Shortcut outlined by Apple, there do not appear to be other Apple Store Shortcut options available at this time. Full release notes for the update are below:
What's NewThe Apple Store app can be downloaded from the App Store for free. [Direct Link]
iPhone Upgrade Program members can now use Siri Shortcuts for an even faster way to complete their iPhone XR pre-order on 10.19. Look for the 'Add to Siri' button while getting pre-approved, and record your own voice command, like "pre-order my iPhone." Say your phrase when pre-order begins, and let Siri pull up your pre-approval in the Apple Store app so you can quickly complete your order.