Hi, I'm curious about this.
My understanding is that pin 10 would control the brightness on boards with this bug - just that it puts a high current on the pin with the danger of frying it. Have you done the test to see if the problem exists on your board, as described by the original poster?
No, I haven't done a detailed test.
Otherwise, I cannot see why DFRobot would not have updated their schematic. Could it be that you are just lucky?
There are 2 schematics at DFRobot, one labeled V1.0 that has the 10k resistor on pin D10 and the other V0.01 that does not have the resistor. So to me it looks like they have updated the schematic. Robotshop.com also has both schematics, but it has a third that is essentially the same as V0.01, and it still has the warning.
Also, you say pin 10 controls the contrast - do you mean brightness? I thought a VR controlled the contrast?
An onboard potentiometer on the LCD shield controls the contrast. Pin 10 controls the brightness. The LCD backlight is visible on the side, and when I set pin 10 to low numbers, I can see it visibly becoming less bright, in addition to the screen.