Until the 3D printer manufacturers embed AI into their devices to recognize firearm designs and restrict the device from printing such parts - I actually think this is likely.
The change in tone from ATF is interesting - first on braces now on 80%. I suspect that shipping the 80% lower with the slide, barrel/upper parts in a single "builders kit" was what crossed the line.
3D printers have so much open source support its ridiculous. It would be like putting restrictions on a lathe or a CnC machine. Now the weapon .stl files... that's where they can make their money.