The items should be re-estimated because they have been partially done and the effort will have
been changed as more has been learned. Whenever an item is not done during the Sprint (for
cancellation or reaching the end of the timebox), it would be moved back to the Product Backlog,
rather than the next Sprint Backlog. This is so, because the Product Owner might reorder them and
they won't be on the top of the Product Backlog anymore.