The Kona is big for Hyundai because they don't have something in the sub compact SUV segment, and they are likely losing sales to Mazda (CX-3), FCA (Jeep Renegade, Fiat 500X, and a few others), Toyota (HC-R), Honda (HRV) to name a few. I don't think it accounts for why a 2018 Tucson hasn't been announced yet. There is stuff floating around out there from Hyundai (USA) with what content changes are coming. That implies that it exists. But I think something else might be going on.
I believe the independent rear suspension is only available on the all wheel drive models. With this feature lacking the new Kona more or less becomes a Kia Soul turbo with reduced space due to the streamlined body. What a shame. We own a 2010 Kia Soul and the main reason I want to get something better is the Soul's poor ride on our bad roads here in Northern California. I don't want the all wheel drive with the added weight and complexity.
Went to a car show a few weeks ago and was disappointed that Hyundai did not have a Kona there. I’ve read a few reviews on Aussie sites and they seem to like the 1.6L Turbo powertrain although the ground clearance isn’t much more than the i30 (Elantra GT). Apparently the Kona sits less than 2” higher than the regular hatch.