The automatic biometric is working as of October 9, 2024 after enabling the settings Unlock with biometrics and Ask for biometrics on launch in the Chrome extension. The settings Allow browser integration and Unlock with Touch ID are enabled in the MacOS desktop app.
MacOS Sequoia Version 15.0 (24A335)
Bitwarden MacOS App Store version 2024.9.0 (21897)
Bitwarden Chrome version 2024.10.0