Revert or more accurately Reload is a convenient feature to have sometimes
particularly when you are trying out lots of differnt ideas and want to have a
point to snap back to rather than using undo repeatedly.  

The reason I make the disctinction between Revert and Reload is because reload
is a more literal description of how it is implemented, but unfortunately this
approach usually comes with a warning asking if you really want to obliterate
the Undo History in the process.   Although it would be much hard to implement
ideally undo would reopen the file at the last save point and that would be just
another action in the Undo history and not obliterate the exisiting undo history.  

I would quite like to any kind of a working 'Reload'/Revert.