The prophecy is that they have violated the contract with the land, and the ultimate curse of the land that corresponds to this failure is that they are removed from power, and someone else will take over the land.
Historical: From 600 B.C. to A.D. 1 we are in the Terminal Olmec, or the Epi-Olmec period. This is a time when the Olmec as a people lose their glory, and the heart of the Olmec culture is destroyed. Historically, the Epi-Olmec is the remnants and restructuring of the Olmec culture. There is a shift from the old power sources to daughter populations that have some of the traits of the Olmec, but which have begun to look to newer inspiration in the development of their culture.