My mistake, you are correct, it should be
The documentation you provided won't change anything you're already doing. So leave that documentation. You'd have to create a global event handler in the MVC application to perform that move/update of that file to a new location in the file system, then update the form record to reflect that change as well
My question to you is why do you want to organize them by form submission in the file system when you can get each file by a form submission using the api?