They just need to find a way to make new housing wards dynamically as the current ones fill and manage it in a way that doesn't stress the servers too much. It's been done before and it is the single optimal solution to make sure that there will always be a chance for people to get a house once they can save up the money to do so, and does so without punishing anyone who currently has a house. This will also completely wipe out housing scalpers as they will be irrelevant.