I, for one, can't wait to join the permanent underclass

Bread and Circuses was the old answer to social unrest.

The new bet is on surveiliance and security tech, the more autonomous the better. The owner class no longer needs to provide bread and circuses when they can constantly monitor for any sign of dissent and deploy enforcers without empathy or morals.

Property rights might not end up as sacrosanct as they hope. There's a series of slow-motion emergencies unfolding, and emergencies are often a place where all rights-- not just property rights-- get curtailed. If they keep up the "Let them eat cake" act, it's going to make them an easy target for a gritty reboot of 1917.

A post-labor world is necessarily a post-capital world. It is pretty impressive that the only way we can envision this happening is by inventing a species of robots that somehow concurrently A.) have all the same reasoning and functioning capabilities as humans and B.) are completely subservient to humans to perform labor. Specifically addressed to TFA: you are already part of the permanent underclass.

There will be no underclass, because the ultra rich will simply let them die.

I'm not sure I believe in this, but I certainly want to.

There is a certain logic to this, and it's not certain it won't go this direction. But creating a solid society for the masses so they don't revolt isn't what most of the out of touch tech billionaires aspire to, from their own public comments.