Well given that most Android phones aren't calibrated but still work for gaming, there's no reason adding noise to 'hide' the EXACT amount of calibration should negatively affect gaming unless they overdo it. I'm not really sure why you couldn't use this to uniquely identify any device, calibrated or not, that wasn't adding noise. Not that there's a reason to do this on Android, since it doesn't go to such lengths to prevent apps from uniquely identifying a device.
The difference between MEMS devices can't be that large or uncalibrated devices would not work properly. Apple's calibration must be precise to an overly large number of digits for it to be detectable to the point of identifying individual iPhones.
I have to hand it to those who figured out these attacks, that's a pretty impressive piece of detective work and engineering. Advertisers must be REALLY struggling to identify specific iPhones to go to such great lengths though.