I can't speculate on what a government might do in the future. The idea behind it is that if, for example, police identify a trend whereby a particular part is used in the creation of ghost guns, but it is not a barrel or not a slide, and limiting access to that part would help reduce the frequency of the creation of ghost guns, the government would have the ability to do that by regulation.
On May 10th, 2023. See this statement in context.