I couldn't see a case for further 457 visas to be issued, but people will need to now accept lower wages as new ventures will not be as lucrative.
I think the point here is that a 457 visa is a temporary permit to work in the country while a skills shortage exists. Such a shortage no longer exists, so it stands to reason that if there is no shortage then there is no longer a reason to continue existing temporary visas, let alone issue new ones.
AWBC