They’re talking about an interconnected web of 3d environments as if it were a new thing. In reality, the idea has been around for ages and there was even a working standard for doing this all the way back in 1994.

Granted, it kind of died out and faded never gaining mainstream popularity. 

Part of the problem is that VRML browsers sucked compared to the games of the time. Doom and Descent were both popular, and vrml had no physics to speak of nor any real easy navigation.