A new feature called "Instant Tethering" is rolling out as part of an update to Google Play Services. With Google Play Services 10.2, users will be able to automatically connect devices together and share an internet connection using a Google account. While this might sound familiar, it is not the same as tethering or creating a hotspot.
Andreas Proschofsky from Google chimed in about the update and explained:
"Google Play Services 10.2 has started to roll out [1] and it"s introducing a pretty nifty new feature: Instant tethering. Basically it works like that: If - say - your tablet has no data connection and you also have a phone connected to the same Google account, it can automatically offer to use the data connection of the phone - zero setup necessary, just a confirmation (well after the initial setup, obviously, you have to agree to use that feature)"
According to the folks at Android Police, the update is currently rolling out to Nexus and Pixel devices that are running Android Nougat 7.1.1.
Source: Andreas Proschofsky (Google+) via Android Police