[dogma1138]

such thing will just make it easier for government agencies to identify both users and hidden services via traffic analysis, so it's unlikely to be implemented.

On the other hand both hidden services, and directories can perform a similar thing. Hidden Services can choose which directories they want to publish their address and identifiers too, this is part of the TOR HS protocol.

Directories can augment any request they get from the user and return what ever value they want, this is how you can cause effective DoS of the TOR network (or any other DHT implementation that does not enforce it's agency over core services) with very small resource investment.