The comment there is not about [-3, 17] being an obscure output range from a distribution. It is that the distribution must be able to handle a random generator

The comment there is not about [-3, 17] being an obscure output range from a distribution. It is that the distribution must be able to handle a random generator that outputs numbers in that range. I think there's a small error there in that the output type of UniformRandomBitGenerator must be actually be unsigned. The larger point still stands though. It is possible to write a conforming UniformRandomBitGenerator that has an output range of [3, 17] and it falls on the distribution to handle this.