From 2 independent sources, I have heard about possible ATF action on demilling requirements in the import space. The suspicion is the ATF will require destruction of any or all of the following:
- gas block
- gas tube
- piston
- trunnion
In addition, Misha, who is pretty well dialed-in to goings-on in the industry, recently claimed to have heard something similar from an industry insider, and he made the obvious points that .gov has a lot of latitude to do so and no court case will be able to undo whatever change the ATF makes.
Time-indexed video:
https://youtu.be/rT3xuYWsdDg&t=109
It is no secret the ATF is not thrilled that US residents have been able to build imports on US receivers since the importation of rifles has been banned. The requirement that any 1 or 2 of those parts also be destroyed or excluded from kits would go a long way toward thwarting the growth of building as a hobby. A decline in the dissemination of knowledge required to build many common patterns of imported rifles would, in itself, be a victory for the ATF as well as the greater disarmament lobby.
As of now, nothing has officially been stated by the ATF or CBP about this.

