Wait a second what are we talking about here? The CDL turns off the traction control? On what vehicle? The FJ Cruiser isn't even made yet.
Traction Control to me makes sense if a tire is cleanly off the ground, so it can just spin and spin. In that case putting on that brake, makes some power go to the other tire still on the ground, so putting a brake on a tire that's not touching the ground is fine (that tire is doing nothing for momentum anyway, it's in the air). Now in a more normal scenerio, where a tire is just barely spinning faster than the other putting on the brake on that tire seems it could be counter-productive. If you could only slow that tire down to match the other tires then maybe it'd work, but not sure if they drag the brakes or pulse them.
However, I think the problem with all traction control systems is what if there is very little traction, so you NEED to spin all 4 tires, some faster, some slower, etc, but spin them all. I've heard the 100-series does pretty good with this and lets them spin. I know the system on a '01 Hummer did NOT do that, and I watched them take forever to get through stuff that any normal vehicle would walk through, because their traction control would not let a tire spin, but to get over a rock, all 4 tires needed to spin, there wasn't that much traction. So that is a problem with all systems, just some have different ways to lock out the system in that case and let the tires just wildly spin..