WOO HOO!! I moved from the butt crack to the arm pit! Oh yea... moving up in the world!
People lived for a very, very long time without pasteurizing their dairy products, in this time they gained immunity to the microbes that lived in it. Today if someone drank raw milk ( although many people still do, especially in other countries) they'd probably get the biggest belly ache ever. With that said, they are baby animals that would be getting similar microbes from their mothers milk to an extent. If the goats are clean and parasite free I would not worry too much. In fact if I had raw milk to hand feed with instead of replacer... I'd probably use it personally.
I also know that some ranchers actually use vit D milk, like you buy at the store, as a supplement to moms with large litters.
Most people use replacers and canned milk because it's more accessible to most people and stores well. We used to hand milk, my mom and stepdad still have four jersey's if I wanted to go milk something I probably could, lol. We had people who would drink the raw milk, and we would mix it in for our puppies "puppy mash" when they raised weimaraners as well.