What might cause warped disk rotors on a truck ?

cheap rotors also will warp much easier, if you use OE (Original Equipment) spec (or better) rotors this will happen much less the price difference really isn't that much and well worth it with the less problems, If you do drive hills a lot, tow or carry heavy loads Ceramic pads will be a better option, they produce less heat, so less prone to rotor warping, any actually last longer and wear the rotor less too, higher end ones even are no dust so your rims don't get dirty if that's something that bothers you too

But so what? Well, apparently this is what happens. You end up with warped disk rotors. Tough break.

Warped rotors are caused by anything that makes them heat up excessively such as hard braking or seized calipers. Also, if your lug nuts are not torqued properly, that can distort your rotor thereby warping it as well.

Poor quality rotors sever heating then sudden cooling.

Riding the brakes is not good.

Check for stuck calipers.

brakes remaining in contact, through a partial apply or if they dont release completely. if air flow is blocked, it will also have an effect but not as fast.

Drove with the brakes engaged like handbrake on.