Hi Dory,
On our end, we have moved the practice to just set a past "expire" date to all users who are no longer with the company, and instructed our customers to do the same.
The rationale behind the "do not delete user" is the Sarbannes-Oaxley laws and all their consequences, as well as the comparable laws in other western countries: we must be able to identify who did what in any customer related and/or financial related data management system.
I have never investigated what happens to the activity logs and the new audit trail if a user is deleted. If the data remains, you can delete the users. If not, much better expire them IMHO. Christina Fuentealba might have the answer 
-Greg
Ah, yes.. This will definitely be a good idea moving forward. I just want to put a policy in place internally that says that we expire users instead of deleting so of course I need some data to back up my request
Good point Greg, maybe I should do this too.
I have noticed a strange thing that when I set a future Expiry date, many users seem to have new dates 1 to 7 days later. I see this when I login and look at the Users a few days later. Has anyone noticed that? Pretty sure no one else is going in there to mess with me 
Hi Josh,
Sorry in advance if I am stating the obvious, but have you checked in the audit trail -> admin trail that no one edited the user?
then, if you double click:
-Greg
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