We don't have inherent support for redirecting one Flipbook to another, but we do have a workaround you can use.
A) Create a custom script page widget, small placement box, on the cover page of the old Flipbook
B) Use the following code to redirect to the new Flipbook once the old loads up:
window.top.location.href = "http://www.publishingdomain.com/i/#####";
(Replace http://www.publishingdomain.com/i/##### with the Flipbook link you want to redirect to.)
The end user will see the old version try to load up, and once the page loads, the widget will invoke and redirect to new Flipbook. It may help communicate to the end user that they need to wait a bit longer for new version of Flipbook to load by changing the old Flipbook name to something like "Flipbook will Load Momentarily"
NOTE: The old Flipbook must remain active in order for this to work. If you delete, disable or set to future pub date, an error message will display when users attempt to load it instead of the redirect script.