I have heard that because of the gear design in the drive that it is better to not change out the oil before hand and go with the manufacturers recommendation. I'm not sure how long a sufficient break in period should be but it will kill me to not change it for 50k miles.
Nothing but an engineering excuse...poor alignment on the gears is causing the wear and noise. As the gears wear in the noise should decrease hence their opinion to let it wear faster. Look at it this way..having clean gear oil in there is NOT going to cause any issues other than maybe letting it be a bit noisier for a little longer. Conversely, oil that has reached it's peak deposit point will cause excessive wear.
The whines we hear are reminiscent of hot rodders who would swap out to larger ratio ring and pinions and not track (align) them properly. They would use a powder and look for an even wear line. If you got it right, nice and quiet with minimal wear, if you didn't, it whined at certain speeds and would dirty up the oil quickly.