"Jan Smith" is returning to my small organization after a few years elsewhere. Her old AD profile ("jsmith") was deleted years ago and does not exist in Deleted Objects. We retained her network folder, so I have the SID for her old account. We haven't had any other users with her last name, so "jsmith" could only have been used for her; she has not used another name with us, so she has not had a different username here. The same applies to her long-deleted email, jsmith@company.com.
I've heard that it's bad practice to reuse AD usernames, but I couldn't find much information on why (except for the possibility of getting two individuals with the same name mixed up) so I don't know if that applies here, or if there are other reasons to avoid reassigning the same name.
If I create a new account for "Jan" and name it "jsmith" like the old one, what problems could happen? Am I overthinking a simple situation here?
Edit: The idea that usernames shouldn't be reused has come from several people I've worked with, often tied to debate on whether to delete or disable disused AD accounts. Partly because it's not uncommon for people in my industry to return to previous workplaces, I've come across lots of different perspectives on "delete vs disable" and accompanying arguments, but not so much for username reuse. I suspect it's just superstition, but I want to see what basis there might be.