DeepThoughts

Here are my policies for deleting groupwise users.
In no particular order

If your account has not been logged into within 90 days, it is disabled, and expired.
If your account has not been logged into within 180 days it is deleted.
(both are from the date of last login, or date of creation if never logged into.)
If you have a rule setup to say “I am no longer at company x please mail me at user@companyY , the account will be deleted, I’m not running a mail forwarding service.
If HR says you are terminated your account will be deleted.
I check last login dates weekly.