Actually, a bit of background.
The control arms are the double arms on each side of the axle that locate the axle front to back in the wheel well. They do nothing for side to side.
The tracbar aligns the axle left to right.
If you lift the truck 2. 5 inches as I am planning to do myself, you will both pull the axle back a bit toward the rear of the wheel well AND pull the axle left towards the drivers side because the tracbar is mounted on the drivers side of the frame.
To compensate for the front to back, the longer control arms from Skyjacker which are probably 0. 5 inches longer than stock, will put the axle back in the middle of the wheel well. You will still experience the axle sticking out about an inch further on the drivers side due to the tracbar.
So bottom line, yes, you will still need an adjustable tracbar that will correct the axle placement left to right. This is one of the two main reasons guys install the DT. The other is durability / ease of maintenance compared to the stocker.
Steve