" I disagree with that part."
All the trillionaires and billionaires already have their bunkers ready, possibly with ways of preserving technology and slaves. This has been known for over 100 years, after all, so if it does happen, they presumably know and have prepared, and their bunkers were built (and are being built) with that in mind. Meanwhile, most of the rest will die, maybe including the people that are somewhat prepared. Particularly if the poles really shift, that will finish off a lot of even the people that manage to survive the floods and all the killing and looting. And even then, most of the people that do survive will have been sent back to the stone age, if not even farther back. So, the most evil people will have the advantage and take over the world once again, unless they fuck up and die anyway.

Oh, and this is not the worst possible outcome. The worst one would be nothing happens and their plans continue, on schedule, with no interruptions and delays.