I'm running iOS 15.0.2 on an iPhone 12 Pro. The response I got was, "I believe this iPhone belongs to Bob," where "Bob" is my first name. Then Face ID was disabled, and the only way I could unlock my phone was with my passcode.
Also running iOS 15.0.2. This did not disable biometric unlock. Don’t mess with Siri, just hold down the power button and either volume button simultaneously for a few seconds.