There is a reason that pilots get basically told the ins and outs of a specific plane. Imagine the outrage if people need to do month long training for a specific car just to be able to drive it (and not just a general "here is how cars roughly work and the laws of the road").

Would it be a vote of no confidence in Full Self Flying?

I mean, they kinda are.

Airline pilots aren't supposed to take a nap, and there are occasionally articles about the various things that have gone wrong because the pilots weren't paying attention.