do they even have a legal argument? It seems their argument is “The SC doesn’t vote exactly as we like, therefore we demand it be changed” and to ‘support’ this non argument, they say “The court is sick and everyone knows it” Without providing any actual proof that ‘Everyone” thinks it
Sort of. They are claiming that there is no longer an issue because New York repealed the law. Unfortunately for them it appears that they only did so because they thought they would lose. As long as they were winning they maintained that the law was Constitutional.
I'm not sure if the Supreme Court ever does it but lower courts have issued "permanent injunctions" to prevent misbehavior from being repeated. Perhaps the Supreme Court could issue such an injunction permanently barring New York from infringing the Second Amendment. That would do the trick.