Google is finally copying this Apple Watch feature for its Pixel Watch - Android Authority

Google is preparing a “Notify when left behind” feature for the Pixel Watch, bringing it closer to Apple Watch and Galaxy Watch capabilities. When your connected Android phone is left behind, your watch will alert you—and your phone will auto-lock for added security.

What it does

• Sends a notification to your Pixel Watch if your phone is left behind
• Auto-locks the phone when separation is detected, including when Airplane Mode disables Bluetooth
• Lets you disable alerts in trusted locations (like home)
• Supports auto-lock with only one watch at a time

Requirements and compatibility

• Bluetooth must be enabled on both phone and watch
• The watch needs to be on your wrist and unlocked
• Some Pixel Watch models may not support the feature; updating software or using a compatible model could be required

Status and caveats

• The feature was discovered via system app strings; it isn’t live yet and couldn’t be enabled in testing
• Builds on earlier work (spotted in June 2025) around separation-based auto-lock
• As with any APK teardown, features may change or never launch
• Correction: when separation occurs, the phone locks and the watch does not

No release date has been announced, but the code hints suggest the feature could arrive in a future update.

Source: https://www.androidauthority.com/pixel-watch-left-behind-notification-3633004/