Two thoughts on payload come to mind:
The current JK has a payload of about 800 lbs.
The JL will have a payload of over 1,200 lbs
The JT will be 1,400 lbs (that's 3/4s of a ton, which seems substantial in a "mid sized" truck)
The JT payload is not a whole lot more than a 4 door JK Rubicon, which makes me feel more comfortable with it's off-road abilities.
The reality of engineering and accounting colliding is, we don't get incredible payload, and off road prowess together. It is a compromise.
It seems the compromise for the JT biases it towards off road capability.
In comparison, according to Car and Driver "...the Maximum towing for the ZR2 is 5000 pounds, and the bed can accommodate 1100 pounds of whatever you like."
https://www.caranddriver.com/news/2017-chevrolet-colorado-zr2-photos-and-info-news
So this bodes well for the JT. Of course nothing is for certain until the mud meets the tires.