The current ruling says that the Lautenberg act only specifies "federal, state, or tribal law", and that since municipal law is not state law, that local convictions to not violate the Lautenberg federal statute.
It would be a whole different level for the Supremes to rule that Lautenberg itself is unconstitutional, because RTKBA is a civil right under the Second Amendment, and so cannot be abridged by federal law. Maybe if Trump succeeds in appointing a couple more Originalists to the Court.
My personal opinion is that once a person has served his sentence, then he is restored to full freedom, and that a man who is too dangerous to be allowed a gun, is too dangerous to be on the streets in the first place.
Thanks