Not sure I buy that last sentence. Why would the system populate these directories with anything other than a) what’s configured to be assigned to the system, and b) what the caller requests to be created by simply opening a specific path?

Sure, you could script opening each address of the entire address space and have an unfortunate situation, but you don’t get that by default when you simply query what exists.

That said, it’s been a veeeery long time since I tried out Plan9 and Inferno.