Hello,
The Wallet App should keep passes updated on any iPhone you are signed in with you Apple ID. Have you checked to make sure your are signed in? Settings App > Apple ID > iCloud. Make sure you have Wallet enabled and Keychain on.
Manage your passes in Wallet on iPhone - Apple Support
"Change the settings for all your passes
- Keep your passes up to date on your other devices: Sign in with your Apple ID on your iPhone, iPod touch, and Apple Watch.
- Note: This setting applies only to passes in Wallet, not to cards you use with Apple Pay."
Sign in with your Apple ID - Apple Support
If that doesn't help you could likely add the pass to your new iPhone's Wallet app from a email confirmation of the purchase, if you have one, since the tickets have not been used yet.
Add and use passes in Wallet on iPhone - Apple Support
"Add a pass
You may be asked to add a pass within an app after you perform an action such as purchasing a ticket. Or, you can tap Add to Apple Wallet when you see it from the following:
- Wallet-enabled apps
- Mail or Messages
- Web browser such as Safari
- AirDrop sharing
- Wallet notification after you use Apple Pay at a supported merchant
- QR code or barcode
- To scan the code, open the Camera app
, then position iPhone so that the code appears on the screen."
I hope this helps. If not, contact the ticket seller to let them know about the situation and ask for new tickets.