Pages does not automatically save the original. The moment you close an edited Pages (or any iWorks) document you lose any ability to go back to the original, unless you made a copy of the original yourself before editing. Before you close the document you can use Undo to recover from recent chagnes. This is not unlimited. If you’ve doen a lot of editing you won’t be able to Undo back to the original.
So, if you need the securithy of an original document when using Pages, be sure to work from a copy.
If you use iCloud to sync your Pages documents, it is constantly updated, and will update any of your other iCloud connected documents the moment you open Pages on them. You can not rely on iCloud to revert to an original. It doesn’t work that way.
If you need a way to work from the same original over and over (kind of like using a template) you can simulate templates, sort of. Here are a few methods to consider.
Using iTunes Sharing: No iTunes Required
After you create the original document, with the fonts and/or other defaults you want, tap the Share icon, Send Copy, then iTunes. Use the Pages format to save it. This places a copy of the document in a special area reserved for coping files to and from a computer using iTunes. It will stay there unless you intentionally delete it either on the iPad, or in iTunes when the iPad is connected.
The next time you want a document with those defaults choose the Copy from iTunes option instead of Create Document. It takes the same number of steps as Create Document, so it's not a big hassle once you've set it up.
The advantage of doing it this way is that you never have to worry about accidentally editing your original, because a new copy is created, just as if you had used one of the templates.
If you want to delete a document copied to iTunes on the iPad, start out by choosing the Copy from iTunes option when creating a new document. Once you see the list of documents you can swipe them to get a Delete button.
I'm not sure how stable the iTunes file sharing buffer is. It may be possible to delete it through some sort of reset (though I've never seen it happen). That means you should also have a copy of your templates saved elsewhere, preferably not on the iPad, just like any other important document.
Using WebDAV: Internet Required
Another, similar solution is to use a cloud file service that supports WebDAV. Box.com does this, and I use it this way fairly often. The steps are exactly the same, except you use the WebDAV menu items instead of iTunes. The first time you choose the WebDAV option you will have to set up the server. Instructions should be on that service's site, somewhere.
In Box.com’s case it is
and your username/password.
The advantage over the iTunes method is that you are also creating a backup copy of your templates. One that won't get deleted if something happens to your iPad. It's also a good way to save your important documents, ones you can't afford to lose. You can't rely on iCloud for this, because iCloud is mostly meant to sync your documents between devices; it updates much too fast to be considered a backup. Mistakes become irretrievable very quickly.
The disadvantage of using Box is that your templates are online and can not be used without an internet connection.
Other:
You could also use a local file storage app like GoodReader, or use local (favorited) files in DropBox, Box, Google Drive or other cloud services. However, with the recent iWorks file format change this has become tricky. I don’t recommend it until Apple (and the others) figure out how to handle the format reliably.
