[Samsung Galaxy Z Fold3] ianmacd:
Yes, my Fold3 (F926B) arrived yesterday and I unlocked its bootloader this afternoon.

I can confirm that all cameras stop working afterwards. This means that facial recognition also fails. Anything that uses any of the cameras will fail.

I tried installing a third-party camera app, but this also failed. I took a logcat of the failure:

07-12 13:50:51.413 1384 31574 W ServiceManager: Permission failure: android.permission.CAMERA_OPEN_CLOSE_LISTENER from uid=10291 pid=8927
07-12 13:50:51.413 1384 31574 D CameraService: CameraDeviceState for CameraManager
07-12 13:50:51.413 8927 9780 I CameraManagerGlobal: Camera 0 facing CAMERA_FACING_BACK state now CAMERA_STATE_CLOSED for client net.sourceforge.opencamera API Level 1
07-12 13:50:51.413 8927 9780 I CameraManagerGlobal: Camera 1 facing CAMERA_FACING_FRONT state now CAMERA_STATE_CLOSED for client android.system API Level 2
07-12 13:50:51.413 8927 9780 I CameraManagerGlobal: Camera 2 facing CAMERA_FACING_BACK state now CAMERA_STATE_CLOSED for client android.system API Level 2
07-12 13:50:51.414 8927 9780 I CameraManagerGlobal: Camera 20 facing CAMERA_FACING_BACK state now CAMERA_STATE_CLOSED for client android.system API Level 2
07-12 13:50:51.414 8927 9780 I CameraManagerGlobal: Camera 21 facing CAMERA_FACING_BACK state now CAMERA_STATE_CLOSED for client android.system API Level 2
07-12 13:50:51.414 8927 9780 I CameraManagerGlobal: Camera 23 facing CAMERA_FACING_BACK state now CAMERA_STATE_CLOSED for client android.system API Level 2
07-12 13:50:51.414 8927 9780 I CameraManagerGlobal: Camera 3 facing CAMERA_FACING_FRONT state now CAMERA_STATE_CLOSED for client android.system API Level 2
07-12 13:50:51.414 8927 9780 I CameraManagerGlobal: Camera 4 facing CAMERA_FACING_FRONT state now CAMERA_STATE_CLOSED for client android.system API Level 2
07-12 13:50:51.414 8927 9780 I CameraManagerGlobal: Camera 52 facing CAMERA_FACING_BACK state now CAMERA_STATE_CLOSED for client android.system API Level 2
07-12 13:50:51.414 8927 9780 I CameraManagerGlobal: Camera 71 facing CAMERA_FACING_FRONT state now CAMERA_STATE_CLOSED for client android.system API Level 2
07-12 13:50:51.414 8927 9780 I CameraManagerGlobal: Camera 73 facing CAMERA_FACING_FRONT state now CAMERA_STATE_CLOSED for client android.system API Level 2
07-12 13:50:51.414 8927 9780 I CameraManagerGlobal: Camera 91 facing CAMERA_FACING_FRONT state now CAMERA_STATE_CLOSED for client android.system API Level 2
07-12 13:50:51.415 1384 31574 D CameraService: getNumberOfCameras E
07-12 13:50:51.416 1384 31574 W ServiceManager: Permission failure: android.permission.SYSTEM_CAMERA from uid=10291 pid=8927
07-12 13:50:51.416 1384 31574 D CameraService: getNumberOfCameras X: ok
07-12 13:50:51.416 1384 31574 D CameraService: getNumberOfCameras E
07-12 13:50:51.416 1384 31574 W ServiceManager: Permission failure: android.permission.SYSTEM_CAMERA from uid=10291 pid=8927
07-12 13:50:51.416 1384 31574 D CameraService: getNumberOfCameras X: ok
07-12 13:50:51.416 1384 31574 D CameraService: getCameraInfo E: 0

At a glance, I'm confident that this can be fixed using Magisk (i.e. root), but I can't rule out the camera having been disabled in other ways, too. The situation may not be recoverable.

After relocking the bootloader, the camera works again.

It's really obnoxious of Samsung to do this, and I am in two minds now about keeping the device and working on a fix for the issue, or simply returning the unit in disgust. This is the kind of practice I expect from Apple, and I always tell Apple users to vote with their wallet when confronted with such anti-consumer practices.