WordPress launches 100-year domain registrations for $38,000

Not only won't we be able to afford property.

There won't be any domain names under 20 characters available.
So what happens when they go bankrupt?

There is currently no 100 year offer by any registrar across the globe. I suspect they will use an initial amount from your payment and renew it for 10 years. They will likely re-invest the remainder and renew your domain every 10 years. So, if they go belly up, I see a situation where they will likely transfer your domain back to you, and you will be responsible for future renewals. If you passed away obviously it is all gone.
Some more bad research at play here. This is an offer by Wordpres.com, not "Website web content management system and hosting service WordPress".

The two are separate entities. It's like calling me an Editor on MyBroadband because I wrote this comment.

Relating to the offer, it's worth noting that it includes hosting, so would come up to about R600/m for 100 years.

I'm sure that inflation would make it worthwhile.
Then again, I'd happily take the 700k and invest it somewhere instead!