It's not only the controls that are different between the two systems. The HVAC housings are also different. In order to swap that out, you have to take out the entire dash, drain all the coolant, and evacuate the AC. Big job, not for the faint of heart, and also extremely expensive.
If you have the tech manual for your truck, you'd be able to figure out what's involved. But yes, it is a fact. Dual zone systems have an HVAC box with two blend doors, one for each side of the cab. Single zone systems have an HVAC box with one blend door.