State laws, do not supersede federal laws.
If a state passes a AWB after passing one of the "firearms freedom laws" then it would be a state matter, but if a federal AWB passes, it supersedes what the state wants to do.
It would have to go to the SC, and be ruled upon, and they wouldn't have to enforce it till it had been, but thats not what they're doing or saying.
Before anything has happened, these LEO's are saying, we're not going to obey any laws that we don't agree with, and there's nothing you can do or say about it. Before any law is passed.
"If there must be trouble, let it be in my day, that my children may have peace"