Grade: Very mixed
Milk, yogurt, and cheese are either bad neutral or beneficial depending on who you ask, what study they believe, and what fat content is being considered. I’ve read more than I care to remember and the answer still isn’t clear. This blogger had the same conclusion in 2012 and goes into much more detail.
I love nearly all dairy, so with great personal bias I will go out on a limb and say that it’s probably ok to have moderate amounts of each so long as you opt for the fattest grass-fed version you can find. Also, it’s probably best to avoid skim and low fat dairy which have been linked in at least one study to Parkinson’s.