Zuck-level money wouldn't matter in a situation where a bunker is needed though. In a post-money situation, Zuck doesn't have anything to offer compared to a random man, so nobody will have any reason to join and partake in his "village" plan.
A really serious (or at least as close to serious as we can get when imagining apocalyptic scenarios) plan would be to stockpile goods/food/a means of production - those things are what's going to be valuable once shit hits the fan and might actually convince more people to join him.
We're entertaining actions the rich take in preparation for a societal meltdown: build a bunker vs build a community. They take them now (hence the article).
Starting to build a bunker (or a community) in a post-apo world would indeed be a little too late for Mr. Zuckerberg & co.
> A really serious plan would be to stockpile goods/food/a means of production
You need loyal people first and foremost. Leadership and trust. Otherwise disloyal people (historically, your own guards / companions) take whatever you've stockpiled. Yours is that Grade B strategy I was talking about.
Your "goods/food/a means of production" are only useful insofar other powers uphold the overarching social structures & rules. To the extent that premise is fulfilled, I'd call such meltdown only a minor temporary hiccup. Beyond that, your stockpile and remote fortress is not much use. You need loyal people.
I mean, it takes a pretty dumb billionaire to not realize that when a real crisis hits, you'll be a sitting duck (mostly for your own guards / security), in your fancy bunker or forest ranch.
That's more of a naive plan for your run-of-the-mill rich guy, the lower echelon of "rich". Mere $100M-1Bs.
I always thought Zuck-level money gives you better options, such as building your own loyal community. At least village-sized and quite diverse. Which is what you really need when the shit hits the fan.
But maybe Zuck's building that too? And the bunker only a red herring, a hedge for minor temporary hiccups.