I’ll be curious to hear what @FordTechOne says, but this does not have a ‘metal on metal’ sound characteristic to me. EB is noisy at start up and this doesn’t sound like a problem to me, just a quirk.
Sounds absolutely normal to me. These engines have a complex cold start strategy in order to meet emissions, as does any other turbocharged direct injection engine regardless of manufacturer. The 3.5 Ecoboost runs through a gamut of self tests and executes extensive strategies to maintain cold start emissions, including varying pressure in the Direct Injection (DI) system, turbocharger wastegate actuation, and camshaft timing cycling.