There is opportunity to rearrange things, but it is limited. You need to tell your readers what happened, and make sure the plot works for both readers who accept the change and those who don't. I'm guessing it works best to limit this to corrections ("last week I said that Joe did X, but of course he died last month - it was supposed to be Joe's cousin Frank"), but it is an area that I doubt it well explored to see how much readers will accept.