What kind of political leverage do the useless have? This isn't a realistically sustainable outcome.
Today, people have leverage because removing them has real economic consequences. With AI, we need to be on the useful side of the divide to have any leverage.
And then we'd better hope AI has respect for property rights.
Property rights might be the least of your problems.
What kind of political leverage did a French peasant have in the 1780s?
Apathetic mass-murder is unjustifiable, and the ultrarich would need to justify it to their families, who would then need to justify it to other people they know, and so on. And remember that we're talking about the majority of the global population, an event like that couldn't be hand-waved away like one would do for a minority group.