Scammers will just start the process and call back the next day. There is an entire genre of scam relying on slowly building rapport and only cashing in once all the way at the end.
Unfortunately that's your own misunderstanding. iOS (as well as modern android) quite effectively prevent phone theft while the electronics are in transit along the last mile of the supply chain. Anything beyond that is a happy accident.
(I'm being a bit overly cynical there but IMO only the tiniest bit.)