This is why a worker's rights movement is important. You shouldn't have to rely on your employer's goodwill. Reasonable privacy rights on work equipment should be guaranteed by law, and any large company should have a Euro-style worker's council.

The legal environment is the only way to baseline behavior. In countries with strong worker's rights, you generally don't have to fight much to make use of them; it's the norm for management, too. Likewise, the US-style norm of having no expectations toward your employer and the "stay in your lane" type takes rampant in the thread are also symptoms of the environment and its norms.