The strength of this is its weakness: because the worlds are generated procedurally, they cannot contain dependencies between the elements of the world, unless they have been specified in the formula. The article gives a good example, of how a river can't emerge from the slopes of the terrain - instead, you have to encode the river as part of the terrain. It's not emergent. It's analytical, not numerical.

They can still have a sophisticated generation method, which does encode several different features, that can co-occur in unexpected ways, but it can't be a deep interaction. In effect, the designers are exploring the space of equations for world generation. The advantage is they can have billions of planets without storing them or expensively generating them. Analytical solutions are extraordinarily efficient - it's just a formula, you punch in the seed and you're done. No iteration or search.

In the videos I've seen, the planets all look alike, just different shapes and colours for trees, grass, terrain.

Still, I admire their dream and fervor and hope it's more interesting than I expect.