We have an access level that is called "Deactivated User" and it equates with "Reviewer" so that we can distinguish between actual reviewers and former team members. We leave them on their teams and groups so their work will appear on the appropriate reports.
For security reasons, we change their email address/username to a dummy address on their last day so they can no longer access the account and so others will receive a bounce-back if they attempt to message them directly. However, this does create a scenario in which someone may be tagging them in updates not realizing that no one will see them.
At this point, we haven't created a process for actually deactivating their account because the data from the past is still relevant for us. That's on my "rainy day to-do list" to figure out, so if anyone has any additional ideas, they would be much appreciated!
