This is some leftist BS story, like when they claim 5 guns and a thousand rounds is an “arsenal”.
The ATF recommends (or straight out lies about) a lot of things that are not legally required. People simply comply because they are afraid and do not know their rights. This story should have been quashed when the reporter learned there is nothing illegal about selling unregulated gun parts. Well, unless of course there is a leftist agenda at play.
Another example of ATF “recommended” actions are notifying them of an intrastate move if you have SBRs. Nothing legally requires you to tell the ATF you’ve moved to a different address in the same state if you have an SBR. But their Form 4 wording is carefully chosen to imply such an obligation. The ATF doesn’t enforce law, they make crap up and try to trick people into waiving their rights.
Yes, they use the legally-ambiguous term, “shall inform.”