No. They all need to do an Overeem. Come in and fight a top contender. If they destroy them, then title shot e.g. Overmeem. If they win unimpressively, another fight first, that is what should have happened with Shields. If they lose then tough luck and let them work there way up the ranks e.g. Lombard or Pettis.
Gil Melendez, Marquardt, Rockhold and Cormier are all great fighters, but they are not well known enough and have not done enough to warrant an instant shot. Giving them a casual UFC fan intro fight will probably damn near double the PPV for the title fight over an instant title shot.