Are there any Laws that protect a seller in a case where both the Realtor and the Buyer are aware of future increased value in land that wasn't disclosed to them?

Yes, there are laws that protect sellers, particularly regarding disclosure requirements. Sellers may not be liable if they did not have knowledge of the future increased value or if they provided all required disclosures honestly. However, if the Realtor or buyer can prove that the seller had knowledge of material facts that could affect value and failed to disclose them, the seller could be held liable. Legal outcomes can depend on specific state laws and the details of the situation.