I.N.
It's bad for them if they're allergic to it. Even though soy contains phytoestrogens, billions of asians eat soy and drink soymilk every day and are fine. It's not bad for them. I wouldn't, however, switch because of a perception that it's better for them. If they can tolerate cow's milk, you can stick with it. Goat's milk is also very nutritious. Your kids should get plenty of vitamins from other foods they eat. You can always supplement with a multi-vitamin if you're concerned about their intake.
To be clear, there is NO REPUTABLE RESEARCH which links soy to extra breast tissue, underdeveloped sex organs, or anything else.
BTW, a food labeled "natural" is not necessarily organic. To be considered organic, it must meet strict requirements of a certification association, such as Oregon Tilth. The grocery stores (Harris Teeter does this a LOT) will frequently label something "natural" in order to charge a premium price.