That may have been the purchaser's expectation, but their deal was with the seller (and bank), not the community in general. In none of the legal papers I sign

That may have been the purchaser's expectation, but their deal was with the seller (and bank), not the community in general. In none of the legal papers I signed when purchasing my home was any arrangement with the city constraining future construction nearby. That's done with my vote (so without much effect) and any political action I can spur.