The issue with this, and all one-way whisper roles is that its always possible for the whisperer to set up a coded response system so that the target can communicate arbitrary information to the whisperer in secret. The only limits are those of patience, rigor, and imagination.
For example, the Telepath could whisper a player "claim your role to me in secret by starting your next sentence with a word 1-blue/2-doc/3-cop/4-vigil letters long." The one-way whispering role can do this for any information he/she would need, so the player might as well have a /respond function.
The same sort of logic can also apply to whisper setups in general due to leaking, making optimal pro-town behavior for those setups needlessly complex and steeped in policy.
The role isn't useless, but it doesn't quite have as much purpose as the mafia version. Still, should be a nice add as a weak PR that can't be CCed (unless combined with Whisperer in the same setup) and has added value in no-whisper games.
Boring role. At best, it is a copy of the town crier, an anonymous clear. At worst, it is a spammy role that cant even clear itself or be useful because of the possibility that it's actually the whisperer. I can't see the maf sided version being more useful than spy at all.
