Re-Uploading a Listing, New UPC?

I didn’t know there was a difference between brand approval and brand registry. I didn’t bother trademarking my product because I am a new seller, and listed it as generic. But, recently I learned you can get brand approval without the trademark, and so I want to re-list my product under a brand name, and get brand approval.

Is it possible to re-use the same UPC as my original listing? I already placed an order request to my manufacturer, and the product will be shipped soon. I used the UPC as the manufacturer barcode to ship the item to the Amazon warehouses, and I am worried if I change the UPC/ listing, Amazon will reject the shipment.