I suspect that they need to worry about xboxes using default time settings.

An Xbox One can easily sit on the shelf for 3-4, or even more, years before being sold. Not quite the typical use-case...

Using your powers of divination, given that the platform has only just had its second birthday?

Probably entrail reading, which is more applicable to the games industry than divination. That, and the 30 years of console sales patterns to draw on.

Huh?

Look, I guarantee there's a game shop in Small Town, USA, right now with more Xbox One consoles on their shelf than they'll sell in three or more years. And I guarantee you'll find "new in box" Xbox Ones on Ebay 8-10 years from now.

Even if Microsoft stopped producing new Xbox Ones this afternoon, it wouldn't magically make those ones disappear.

Heartbleed showed us that many certificate authorities reissue certificates from the original date they were first issued.