You're right. The owner/driver has to approve the update, if I recall. But putting responsibility to review and understand release notes on the car's owner seems kind of absurd. And that's assuming that you have accurate and descriptive release notes, which was most certainly not the case for the described instance. In any case, clicking "update" is such a rote behavior for users on computers, phones, and now their Teslas, I'd argue that it's effectively no different than an update happening without notice or user intervention.

There's only so much you can learn from even the best release notes, period. The ever-so-common "bug fixes," for example, is so broad that it effectively means nothing at all. At best, it's telling the end user "this little update just changes some stuff hidden under the hood. You won't notice anything, so don't give it any thought."