Well, I always edit old code. So whether old saves work or not is always a gamble. Sometimes they do, sometimes they don't. It depends what you're loading into. We implemented the Act Selector to alleviate some of the headache associated with this. So instead of starting new every time, you can just start from the Act you were on before. I know it's a pain in the butt, but technically until the Completed version of Avalon, I consider Avalon to still be in Beta. And I like to go back through and polish constantly.
Hope you're enjoying the update.