I think what you're looking for is a Journal report where it shows the object (project/Task), the field name, the change type, The object changed, old value, new value. If you're looking for just a list of system updates the way they're displayed in the updates section, I've never seen that done.
Here is an explanation of the "Note" fields gathered from my tests and coupled with an explanation from Workfront Support.
Last Note: Available on any object that accepts updates. Any update that is entered directly on the object, or sent directly to or from the object (user on a user report) by anyone, ignoring all others such as Proof Comments or any other child objects. In a user report, these are often private convos.
Last Status Note: User object only. This field is NOT available on Projects, Tasks, Issues, etc. compares Last Entered Note and Last Update Note and returns the most recent of the two.
Last Entered Note: User object only. This field is NOT available on Projects, Tasks, Issues, etc. returns the last update a specific user made on their own User page. (No one at Workfront was 100% sure on this one.)
Last Update Note: User object only. This field is NOT available on Projects, Tasks, Issues, etc. returns the last update a specific user made on any object. The Last Note entered by the User, ignoring any other subsequent Last Note entries created by other users. A User report lists only the users entries (as they own themselves) even if the update is on another object (proof, project, etc.), These may be private convos.