We understand that its still quite early to even be talking about rumors and leaks surrounding a Google smartphone that wont be announced for another six months. However, this is the first official mention of a Google Pixel successor, though probably by accident.
XDA-Developers reports of a new AOSP commit (a modular piece of code dedicated for a particular function of the Android OS) called Cherrypick decide which Auto Selection Network UI to use. has a description that mentions the Google Pixel 3.
This change added the config because the HAL V_1_2 only supports Pixel 3, and the new Auto Selection Network UI is based on HAL V_1_2. So we set the flag to decide which Auto Selection Network UI should be used based in the device type.
This HAL stands for Hardware Abstraction Layer, which is a piece of software that bridges the gap between the Android OS and the hardware, according to XDA-Developers. What this means is that there may be a new kind of bond between software and radio, one that may allow Wi-Fi networks to scan continuously rather than have to hit refresh and wait for a few seconds.
It is believed that Google didnt intend to publicize commits that are meant to be used internally, but it must be hard to keep track of every little thing that involves mentioning an unreleased device without the Android P AOSP and its ongoing Developer previews for both generations of Pixel devices. Wed imagine once Google releases the full Android P source code, we might be able to uncover more about the upcoming Pixel 3.