According to an APK teardown performed by 9to5Google, the option to "Unlock with Voice Match" is slowly being depreciated. The first indication of this was the omission of the aforementioned option on the Google Pixel 3 duo. The Google App version 8.39 for Android has a string of text that reveals the upcoming change. The Voice Match to unlock feature you've been using has been replaced with a more secure way to get personal results while your device is locked. You can change this in your Assistant settings. This feature has been around for a while now. The idea is that Google learns...
Source: https://www.gsmarena.com/google_moves_to_discontinue_voice_unlock_on_android-news-33936.php
