It seems that after an employee is deactivated, their Leave requests linger. for example, an employee deactivated 6-months ago will have a timesheet appear as they had approved leave for that week. In addition, there are pending leave requests from previous/deactivated employees which doesn't go away unless you unlock the timesheet, 'decline', and relock the timesheet. I feel as though once an employee is deactivated, their Leave & Requests should deactivate/vanish with their profile.