Natural iodine is fine in my book, depending on what product we're talking about it being in, and as long as it is in trace amounts (I'm sure it's much better than the chemicals they use now!).
I'd rather have unpasteurized, free-range, organic, hormone-free, grass-fed milk made safer via trace amounts of natural iodine, as opposed to factory-farmed/monsanto artificial-chemical "milk".
Also, I doubt that very many vegans are aware that their gripes related to health-issues and the consumption of milk stem from the fact that most milk nowadays is not unpasteurized, free-range, organic, hormone-free, and grass-fed.
In other words milk can be good for you, whether vegans like it or not (and I do by the way respect the vegan lifestyle, even though I don't always agree with it).