Haynes is still good law. The issue is providing information that is an admission of a crime. In other words mandatory registration for a felon or other where it would admit to a crime. It’s a sick irony but because of Haynes and the 5th Amendment Felons do not have to register guns. This is not to say they can escape taxes. That’s a different issue. But, firearm registration laws completely miss the claimed population target and instead apply only to the law abiding.
Felons cannot register guns because they cannot posses them. GCA 68 made it so. A felon in possession has no defense (since I am a felon, registering would be self-incriminating etc), since GCA 68 made it illegal period for a felon to possess arms and or ammunition.
The right to not talk (self incriminate) is still protected, but the action of buying/possessing is made an illegal act.
I think we are dancing on the head of a pin here.
Best.