Our thinking is that you can lay a base quickly, and then iterate on that to work on the details of your game. We want to avoid the analysis paralysis that comes from having to make all of the decisions upfront; you can instead rely on the AI's "common sense understanding" of the world [0] to get started, and then refine it to your desired vision.
Our initial "engine" is highly-constrained with a specific ontology and predefined behaviours. That will strongly restrict what can be built with it. That's what makes it tractable to use with today's AI; as we develop better techniques and the backing models get better, we hope to cover more and more of the game design space.
[0]: Yes, this is a contentious concept, but in practice it has a pretty good idea of what an orc is :-)