A nice quote from the FAQ page on the ESAP website
QuestionWhen will the airport be closing?AnswerThere are no plans for Essendon Airport to close. As part of the lease the Australian Federal Government requires Essendon Airport Pty Ltd to maintain the airport for use by aviators. Airports in major cities are considered transport infrastructure of national significant by the Commonwealth. The lease which requires aviation to continue upon the site expires in 2098.