The Pixel 6 and Pixel 6 Pro currently only support one biometric authentication method, which has its issues. However, Android 12 code has revealed that Google has been working to bring face unlock to the pair with a feature codenamed 'Tuscany'.
https://www.notebookcheck.net/Google-has-left-code-in-Android-12-to-enable-face-unlock-on-the-Pixel-6-and-Pixel-6-Pro.578356.0.html
I honestly doubt they would support face unlock.
In order to get an accurate depth profile you need two cameras, and with IR sensors at that. Security would suffer a lot. Google as an organization cares a lot about security, and I doubt they would give away security to gain ergonomics.
That developers are experimenting with this merely suggests face unlock for future Pixel releases.