It means the rich no longer needs the poor. If robots also replaces the military it means that the rich no longer needs to fear the poor. With both of those out of the equation things aren't looking great for the poor.
This does not even make the slightest sense, who cares about money when you can subjugate the masses in other ways. It is only a power game at this point.
And if most of the population becomes useless, why would any psychopath keep them around? I’m sure it can’t be that hard to exterminate most of the humanity.