My guess would be it was either scrapped, or turned into the new PS exclusive Jade Rabbit scout rifle and given a different name. This is the reason I put no stock into leaked and datamined items from Destiny. Doesn't seem like the Fate of all Fools will be obtainable anytime in the near future either. More often than not, whatever is leaked is only a placeholder and the end result is either partially/completely different, or removed from the game altogether.