This is possibly the best thing to happen to wild rhino populations. I don't see how this is any different to farming cows, chicken, pigs or any other animal.
There will always be demand for rhino horn, so it makes sense to satisfy that demand in a way that does less damage to the wild population.
There will always be demand for rhino horn, so it makes sense to satisfy that demand in a way that does less damage to the wild population.