I don't believe you can subscribe to edits, notifications would typically hang of the comments/replies.
Nicole, you can do this for TKBs that have been edited. Click on your Avatar > My subscriptions > Notification Settings > Scroll to "Edits to published knowledge base articles and topics in areas I subscribe to".
Is this what you are looking for?
That would have been perfect if we had TKBs. Unfortunately we don't have them, and they won't be turned on anytime soon. Thank you though @CrystalL!