Great. You had to go and post this.... now I hear it too, and I can't unhear it! I have no idea if it just kicked in around 6 months/3500 miles of riding, or if it was there all along but I never noticed it until you brought it to my attention. It's not there until I've ridden it for a while, though, i.e., not on a cold startup.
Well I have nothing to add except to say that you're not alone and you're not nuts, and hopefully a bit more detail on "that's normal" from your dealer's mechanic can be supplied by someone here.