duplicate device due to phone name change

My iPhone 12 Max Pro died. Support replaced the phone. I used the most recent iCloud backup from a couple of day prior to the phone getting replaced. So, logged in and iCloud shows both devices. I changed the name of the phone and still see the two devices. Is it safe to simply delete the old device now that the restore has completed. Or, is there a method to simply keep it as a backup and not have it show up under the devices?