Ever heard of Julian Simon? Look him up. He devoted much of his life to pointing out (correctly) that every single prediction of impending disaster due to shortage of a particular commodity turned out to be wrong.
True, but hindsight never guaranteed a future. It would be nice indeed, if more phosphate were found adequate for all anticipated future needs. Mere discovery of phosphate does not guarantee use as the EPA and other federal agencies have a lid on mining, especially open pit mining as exists with phosphates.