Completely different scenario.
It's the exact same scenario.
Feds were enforcing a current federal law not bound by a Constitutional Amendment.
You'd be correct if the Feds were attempting to enforce a law that has been ruled unconstitutional but we're talking about a law that hasn't even been passed much less ruled unconstitutional.
Not every law restricting a Constitutional right is unconstitutional. That seems to be your suggestion. And there has never been a case which states there can be no restrictions on the 2nd Amendment.
Scaliar in Heller wrote:
There seems to us no doubt, on the basis of both text and history, that the Second Amendment conferred an individual right to keep and bear arms. Of course the right was not unlimited, just as the First Amendment ’s right of free speech was not, see, e.g., United States v. Williams, 553 U. S. ___ (2008). Thus, we do not read the Second Amendment to protect the right of citizens to carry arms for any sort of confrontation, just as we do not read the First Amendment to protect the right of citizens to speak for any purpose.
But it's a bit premature and in fact grandstanding for any state to claim what these are saying considering no law has been passed.