Other than a hub being flagged no one is aware of changes made. If you want the changes known to a search engine do the following.
In the search bar type "your writing nickname" "your keywords" "hub title" "date"
hit search. The one caveat to this is you should have the date of revisions in the hub. We used to change the copyright date, now we add a second. If we revise more than once we remove the revision date and replace it. The reason we do this is too many copyright changes with your name attached will turn a hub to spam.
A word of advice learned the hard way. When you publish make sure your copyright is in place like so © date, time, name, rights reserved. Someone copied a hub, had it on another platform within five minutes of my posting and I was flagged for duplicate content.