I don't think Rob and is collaborators are making that claim at all. From the OP:
"We do not yet know what the ideal diet for a human is, but our present understanding permits us to easily design a diet that is far superior to what most people are eating."
He clearly states that they are making no claim to providing the ideal diet. They are simply on a mission to do something better than we have. I cannot predict the future so it's possible that he and his partners get rich and stop trying to improve the formula.
I would hope that instead they continue their research and further refine their formula over time and science finds out more about our bodies and their necessary nutrients.