Grumble, grumble, grumble…
The new second generation nest “hub“ isn’t a hub at all. It’s a smart speaker with a display.
Connectivity
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Wi-Fi ∙ Bluetooth ∙Thread 1
.
(1) Functionality not yet available.
So ignore anything any well-meaning bloggers write about thread. It’s not turned on yet. 
It looks like it has the same integration with smartthings that the first generation hub did, and does not seem to be part of the new nest integration yet.