Unsure if there will ever be a multitude of options produced for the 6th gen due to the narrow sizing of the upper grill. I believe that it would be difficult to create a different style grill with such limited space. Developing the grill would require a lot of R&D and I have seen very little interest on the forums in regards to a new upper grill so vendors probably figure there isn't enough demand and little return.
just my guess.