ding ding ding.
totally right. Always be carefull when removing wheels, storing them, etc. they are easily knocked over and since they protrude from the wheel edge, take a hit and bend. And like you said from MX, always got hit and bent from other riders and crashes. I had that happen on my CRF way back, I cooked pads and had the lines expand to the point it cracked the little plastic clip holding it on the fork leg! I had about 1/8" runout and a good sized nick from the impact that caused it on the rotor.
Unless the wheels were knocked over when getting tires put on or what ever, or the bike was rested or tiped over on something its unlikely they are bent from impact. And the KMI on the bike I doubt they are warped from use. So I dont know, but def check the runout.
take the calipers off and make sure the slides are smooth and not binding up too, just like on a car.