I think this was an error. I have seen that before but Jeep corrected the owners manual on later 2015s. All 2 doors as far as I understand are rated at 2,000 lb and 4 door at 3500 based on the wheelbase.

 

I will not discuss what is or isn't legal. I have a 2012 jku with max tow package. I've towed a toy hauler as heavy as 5000 pounds. The factory receiver worked, but not well. I used a weight distribution hitch and the torsion bars caused the relatively weak cross member to twist a bit. I replaced the rear bumper with the smittybilt XRC bumper which is rated for 5000 pounds. Wow, what an improvement. I've posted on here about it multiple times when the towing subject comes up. That bumper is fantastic. Now, equally important is stopping ability. My toy hauler had brakes and I have a brake controller in my Jeep. If your tow does not have brakes, I'd say may still be possible, but drive like a grandma with tons of stopping distance allowed. Don't want the tail to wag the dog.