If this goes farther, does it negate Lautenberg?
Only for convictions in municipal and local courts.
But it offers another strategy for people caught up in the Domestic Violence witch hunt. A person (95% men) could plea to a municipal charge rather than a state or federal charge, knowing that a conviction there would not remove their 2A rights for a lifetime.
My understanding is that such plea deals are done routinely, especially for the multitude of DV charges that are for minor infractions (Shouting, breaking a dish, punching a door, grabbing a hand to keep from being slapped, etc, etc, etc.)
It also allows people who were convicted in such courts an avenue to contest their status as prohibited possessors.
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.