We are moving data for a customer from a big project created years ago to smaller slices. Hence we created new buckets (projects) and move the existing issues into them. The Sprints, since tied to boards which are updated afterwards pointing to the new projects, shall be preserved. Hope there will be an option to do that. Deleting Sprint info should therefore be an option but definitely not the standard approach. 

Moving issues in a project sprint to another project without removing the sprint tie is causing a lot of confusion!  Our team deleted a sprint since this functionality does not make sense (they weren't expecting to see the sprint in their project, and so deleted it unknowingly messing up the other project as well since the sprint deletes completely out of the original project)

It would much more efficient if the sprint assignment was automatically cleared when moving to a new Jira project, or an appropriate sprint from the new Jira project be displayed for selection.

There is a lot of team collaboration and cross-project activities at Adobe, so issues move between projects quite often. If Sprint assignment is not corrected/cleared, that often leads to inability of the "first" team to manage their Sprint because they now require Sprint management permissions under the "second" project, which they are often times missing. That causes a lot of frustration and delays, so hundreds of our teams would be really happy to see this new feature implemented. Thanks!