Note my initial response to this topic; I believe he's speaking to world design thats geared towards reinforcing the gameplay loops of the game.
In a broad sense, this means designing a game world and its lore around the idea that, in say DND, there is an actual, logical reason for adventurers to exist and be able to act as they tend to do.
But you can get as nitty gritty with it as you like, which I related to how Nintendo designed the two open-world Zelda games for this purpose, from broad geography on down to how individual things are placed, all of which are deliberately done so as to support and reinforce the core gameplay loops of exploration and discovery.
And as noted, the Zeldas are fully "gamey" in their world design; they aren't realistically designed in any way shape or form. But, that doesn't mean you can't blend more realism with game needs, it just takes a lot of thought from both ends to reach a good equilibrium.
Ultimately, while theres a lot of crossover, typical worldbuilding methods for books and the like aren't always the best for building gameworlds, and I think OP is trying to get at gameworld building and how thats accomplished, versus just worldbuilding or prepping a fixed adventure.
This in turn tends to mean building up sandboxes and open worlds (which aren't actually the same thing, as unintuitive as that may seem), as these are the kinds of gameworlds that can exist as their own systemic component of a game, independent of any specific adventure or story that might happen in it, rather than just as an over-elaborate set dressing for such things