You're missing the point, which is that we don't normally measure reserves in centuries. We prospect as needed, and there is no reason to think that we would be unable to locate new deposits as necessary. All this and more is covered in the source you linked.
We don't know we have centuries worth of stockpile. That's just an assumption.
In fact, I think it's a foolish assumption to make since if the world's nuclear powers haven't been quietly prospecting the globe for new sources of Uranium since 1945, they sure should have been. But you don't hear about a lot of new uranium mines opening.
And what if this big stockpile us close to a major waterway? Or under a bunch of people's homes?
Acting like "we can just look and find more" as if it's that simple doesn't make sense to me.
We have centuries worth of Thorium in mine tailings alone.
It's considered a waste product, but can easily be used for power, China already has a Thorium power plant up and running. The US had a Thorium test reactor in the 60s.
This article from September 5th claims they are planning a power plant and their prototype reached criticality but was not designed to generate electricity.
If it works, great. That's not a guarantee. Test reactors do not make practical power plants.
The only difference between a test reactor and a live reactor is attaching a turbine.
But that article was talking about one specific type of reactor. The Molten Salt Reactor. Those are good. Completely walk away safe. They also are key for having nuclear power in areas with little water. But they're not the only type of reactor that uses Thorium.
CANDU reactors can burn thorium. It was part of the design specifications. They can also burn natural uranium. i.e. unenriched.
There have been CANDU reactors online for decades...
It was the reactor of choice for something like 20 years, before falling out of fashion.
MSRs are good, but are Thorium only, which wasn't fashionable until recently.
See, prior to about 10-15 years ago, the automatic answer to "how do you get a lot of power in a water poor area" was fossil fuels. Now we have options. Nuclear is one of them, but we need to dust off some older tech and bring it up to modern standards.
That takes time, but less then inventing new types of battery that can handle grid loads.