That’s the wrong argument to make. If that is the argument, then the judges will feel that they have every right to correct what amounts to nothing more than an error in the text. The correct argument is that it WAS their intent to exclude federal exchanges from the subsidies.
Either way. If there was a law with no specific intention, then there is no law, at all.
If they meant what the law says, then they should follow it As written.
Currently they are saying that the backup plan if the states didn't set up their own marketplace was for the federal government to set up a marketplace for them and thus would inherit the incentives provisions from the state plan.