(Correct, it changed. It had been locked before to prevent folks from going through the loophole of buying parts to build a gun).
I was thinking about that earlier today, that's what I'm doing as a summer project. Building up an AK from parts I get here and there. Lot of work and research, I know that when I think it's time to build, i'll find that "this piece isn't staying where it's supposed to", and Ill need to order some more parts. I'm doing it as kind of an experiment, see if I can save money while having new (ish) internals. I was surprised when the parts and accessories weren't locked down.