Procedures and policies, yet. Rights, not so much, at least beyond those disclosures and documents they are legally required to share.

As an example: it is a legally-protected right in many jurisdictions for employees to share compensation information with each other, or even externally. Many (most?) employers strongly discourage this practice, however, and will usually omit the notice that there are legal restrictions on their response in case employees choose to do so. Ditto labor organizing, many types of guaranteed leave, and most whistleblowing protections.

The information asymmetry between most large employers and their employees w.r.t. legal rights is large, and the company's incentives are almost never aligned towards voluntary disclosure.

Ah, so employee handbooks inform their employees of their right to unionize (or refrain from unionizing) without threatening, interrogating, spying on pro-union employees, or promising benefits if employees forget about forming a union?

https://www.nlrb.gov/about-nlrb/rights-we-protect/the-law/in...