A clearer image of the upcoming 2018 Nerf Super Soaker Twin Tide was found on this website.
As expected, the Twin Tide appears to be a standard pump-action water blaster featuring over-under dual nozzle configuration. The newer Nerf Super Soaker models seem to be using their handle/trip regions as part of their reservoir and can do so easily since they have no trigger or other more complex internals in that region of the blaster’s body. As both nozzles are powered by the same pump, taking its apparent size into consideration, either the nozzles will be slightly smaller than usual in order to maintain functional stream range. Time and testing will tell. More information to be posted as it becomes available.