JumpRope does not ever delete mastery data for students automatically, even if they are un-enrolled or marked as inactive. Any account that has been designated to have "Backoffice" permission has access to inactive or un-enrolled student reports.
If you need to access data for a student that is not currently enrolled and your account includes Backoffice permission, you can do so from the "Account & Support" menu found in any of the three modules; Admin Console, Teacher Dashboard, and Backoffice.
Here's a closer look:
After clicking select here, the student's individual Student tab will open giving you access to all of their stored data in JumpRope.
As always, please contact us at firstname.lastname@example.org if you have any questions!