With the recent announcement of the new Pixel 3 from Google, the camera app on all Pixel handsets are due to receive some software updates to support external microphones.
For a long time, recording videos on the Pixel has been good, but the audio quality hasn’t been the best, but the external microphones will be able to plugged into the USB-C port on the new Pixel 3 and the Pixel 2 or using the 3.5mm headphone jack on the first generation.
The new update should come out roughly at the same time as the Pixel 3 goes on sale, this week on October 18th.
At the same time as Pixel 3 launch (October 18th), we will introduce support for Android-compatible plugged-in external microphones in the default camera app for all Pixels.”
Google Engineer – Google Forums