If I understand correctly when you create news streams you can have the option NOT to notify everyone when a new item comes in, but users should have the option to subscribe to that stream if they choose to. Is this correct?
Same for when you choose TO notify, users can opt out. Is this correct?
The reason I ask is because these options are grayed out for all of the users?
As I understand you are testing out New Stream notifications. The first statement is correct, but if users want to opt out of news digest they should have the option if enabled. If this not currently the case as noted I recommend you create a case in your customer group as this sounds to be a bug.