I'm glad this was brought up. I've wondered about this, too. I haven't done apartment shops yet, but I do the BJ's Warehouse membership shops, and they remove your name right away from the database.
When I worked for a large apartment community, we would go through our database regularly and deleted anyone who had not rented for a certain period after our last follow-up. Granted, this wasn't a "chain" of apartments managed by the same company. The management company owned the complex. But it was easy-peasy to do and not time consuming. If they were to clean up their databases on a regular basis, it shouldn't be a "bother." What business wants useless prospect names on file forever?
I learn something new every day, but not everyday!
I've learned to never trust spell-check or my phone's auto-fill feature.