Sure, but a little rust because they weren’t used isn’t a problem, comes off when you use them, but is an instant fail. The brakes are not damaged or broken.

All brakes rust when not used. If you drove around in the rain today, then didn’t drive for a few days, you’ll probably have a little rust on your brakes. You go for a drive and then it’s gone.

If you take your car in for a pre-inspection report, and they see some rust on the brakes, they will tell you to drive it around a bit using the brakes a lot before taking it in to be inspected.

it’s not an actual problem, and not indicative of a poor quality vehicle.

Edit: To be clear - the drivers should be using the brakes more to clear them so it doesn’t build up to excessive amounts which may be a problem at some point, but the test fails them well before it’s an actual problem.

Edit: Also, where the model 3 failed a lot outside of the brakes was the front suspension. There are legitimate problems with the front suspension on the older Model 3s. Those are legitimate fails and are a quality issue (there’s even a service bulletin for at least one of the problems)