Hi @KevinNickels,
Has anyone posted to the discussions already? My guess is that there are already posts, and because of that the anonymous option doesn't really make sense anymore since at least a single name has already been revealed. It somewhat makes sense to me that the option would be grayed out at that point. If you absolutely *had* to change it, you'd probably need to delete the entire discussion and create a new one, but before doing so, you'd need to tell the students who already submitted to save their work, otherwise I could see a lot of valid complaints from those students who might have to the work over again.
Hope this helps!
-Chris