Google has removed an important device feature silently without notice or warning to customers.
NFC Smart Unlock has been removed for all newly signed in Google Accounts on Android. Accounts signed-in/setup from June or earlier are not yet affected. Users that have signed-in/setup their Google Accounts/Devices from July/August 2017 and onward DO NOT have access to this feature anymore.
This was done without notifying users.
NFC Unlock is still listed on the Online Nexus and Pixel Device Manuals. It is also listed as a feature on the online Manual for the Xperia XZ1 which launched with Android 8.0.
Currently no official explanation has been given for the removal. If you wish to continue using NFC Unlock on your device then DO NOT Sign Out of your Google Account or perform any kind of Factory Reset or device Upgrade! You should be safe to install security updates as long as they are on the same version of Android with the same account login session.
This speaks volumes about how Google treats its customers. This also serves as a general warning to be mindful of this sort behaviour from Google. As Android Users we have a right to the features we paid for on the hardware we paid for.
And if those software features need to be removed for some reason legal or otherwise then we deserve a warning beforehand and a reason saying exactly what is happening, why it is happening and what alternative options or potential resolutions there may be.