There are many places where graph theory is used in real applications, but the topics in this article appear to be hypothetical applications, rather than techniques that video game designers have actually used in their games. At least, the author provides no evidence that they are used and many are explicitly described as things the author thinks people should use.
That doesn't make the ideas less cool (and bravo to the author for writing about them), just that the title/intro is misleading.
tantalor•4h ago