Tracked thread notifications should be sent out on an hourly basis, with multiple updates within an hour span being bundled into a single email.
The "comment notification preferences" are unrelated with no forum post equivalent. That's specifically for comments on blog pages, special features, etc.
Hope this helps,
How often does cnet send out mail to indicate a thread has been updated?
I see in my profile this thing called "comment notify preferences" ......does this apply to tracked threads?