Yes, this is 100% true. I just checked it on my own controller. If you can't make it out, it says, "Thx2 allgamefans"!
It's on mine but i have to use a flashlight to see it, and I have to be looking at just the right angle.
If only they could have hidden a cheaper price tag in there as well. This controller is $30-$40 too expensive. There is no way this controller is worth only $80!...