A new feature called Instant Tethering has apparently made its way into the latest version (7.1.1) of Nougat on Pixel and Nexus devices.
In an announcement made on the Google Product forums, Product Manager Omri Amarilio has announced the new feature which uses Bluetooth to detect nearby devices with the same Google account installed to potentially offer a WiFi connection. The tethering feature will ensure your Pixel or Nexus phone has enough battery life, and of course an internet connection before offering to turn on the hotspot.
Pixel, Pixel XL, Nexus 6, Nexus 5X, and Nexus 6P devices running Android 7.1.1 are listed as devices able to instantly share their connections. These devices as well as the Pixel C and Nexus 9 on Android 6.0 and above can request the Instant Tethering function from the other devices.
In their support doco, Google does actually remind users that ‘Some cellular carriers limit or charge extra for tethering’ and advises users to double check before tethering, though this is usually a US carrier issue more than something seen here in Australia.
To enable Instant Tethering, head to Google Settings in your Settings menu, then select Instant Tethering and enable ‘Provide data connection’.:
The next step, for me anyway would be to enable this on Chrome OS devices, with these devices logged into your Google Account and often requiring an internet connection it would be great to see this extended.