Auto Unlock not Supported by Apple Watch Series 3 on Sierra →

After setting up my new Apple Watch today, I was greeted by this message on my fully-updated iMac, running macOS 10.12.6:

Auto Unlock does work with my Series 3 Watch on my MacBook Pro running High Sierra.

Perhaps the updated hardware in the new Apple Watch makes this all more complicated, and wasn’t able to update Sierra to support things correctly.

With High Sierra due out Monday, I have to guess that LTE Watches won’t ever unlock Sierra machines.

September 25 Update: Apple has updated that kbase article, confirming Sierra cannot be unlocked by the Series 3 Apple Watch.