You don't get notifications about questions you don't ask. The closer you can get is to mark the question as favorite. If there is a change in the question, which means the question has been edited, a new answer is added, or a previous answer is edited, you will notice an asterisk in the "favorite" tab that is shown in your user profile page.
As you see, it is not an automatic notification as you would get with questions you ask, and it doesn't help in understanding how many questions have been changed; you need to remember which questions have been changed since the last time you saw that page.
Now the user profile page is going to be changed; you can see the changes here on Meta Stack Overflow. I think the functionality will not be changed.