Actually, I stated on 5thGenRams.com over a year ago that Ram was considering a Ram 4500 pickup to battle the F-450. However, I can honestly say the Ram 4500 pickup isn't happening just yet. The new 2019 Ram Heavy Duty models are so ahead of the game Ram doesn't need such a vehicle just yet.
However, what you are actually looking at in that picture from the brochure is a yet to make its debut 2019 Ram 4500 Limited Chassis Cab. We have had several spy photos of the actual Ram 5500 Limited models up on HDRams.com.
Here is one I shot about a month ago, out testing in Metro Detroit.