To be honest, I'm more surprised that the previous manager can't still see all of the appraisals for those staff that were completed or closed while assigned to that manager. While the members of staff will no longer be on the "MY TEAM" tab, their appraisals would (as far as I'm aware) still be on the "As Manager" tab of "All Appraisals" because appraisals stop moving between managers when they are completed or closed. This also means that the new manager wouldn't have access to the old appraisals.