Would you be happy in a society where everybody lies to you all the time? Lying isn't illegal (except under oath), but it would make for a really shitty society.

You can absolutely expect people to do more than just obey the law. Everybody does. Tesla does not, and that may lead Tesla's employees to use their perfectly legal right to strike. And by your standards, you can't demand that they don't strike, because it's legal.

But it's a shitty basis for a relationship. If Tesla wants its workers to do good work for them, they need to listen to their workers.