This is a project which will cost 100s of millions it is about as far removed from "buying a plot of land to build a house on " as you can get.
It's not really.
Whether it is to build a new abode for oneself or to create a brand spanking new football stadium with all the infrastructure that must by necessity accompany it, one would want to be mad to purchase the "plot of land" without knowing for certain one can proceed as intended.
Mind you, such things have happened before and white elephants owned by bankrupt developers are dotted all over this green and pleasant land