In my opinion, I'd take what Ilyes says publicly with a pinch of salt. I've had good success with PBNs containing sites that have been unregistered for 2 years +. Not saying Illys is giving the world some misdirection, but a 'period of time offline' is pretty open to interpretation... Maybe if a domain has been benched for a decade, it doesn't hold the same value, but I've never picked one up that old. If the domain metrics are still showing well, and links are still live, I'd think they're treated like any other. Just be careful if repurposing, as opposed to recreating.