That is true, the camber angle is not adjustable without the use of aftermarket ball joints.
Here are the specs...
CASTER 7° ± 1 .0°
CAMBER (fixed angle) -0.25 0 ± 0.630
WHEEL TOE-IN (each wheel) 0 .15° ± 0.15°
THRUST ANGLE 0 ± 0 .15°
Caution that the above Caster angle is only for stock size tires. The bigger the tire, the less Caster angle that is desirable. For example, the correct Caster angle for 35" tires is 4.5 to 5 degrees.
Regarding the Camber angle, most Jeeps are long worn-out before the Camber angle needs to be put back into spec.... or wheeled very hard with big tires.