Huawei is building its own DRAM fab, and it could reshape RAM prices for everyone
(www.xda-developers.com)
I mean making the machines to make chips and making a factory that uses said machines are two different things.
True.
There are already factories in China making DDR5 and DDR4 ram now days.
Are they actually fabricating the silicon, or just packaging it?
No slave labor needed. All you need is a modern, advanced, high skill, responsive industrial base which China has.
Sure, like the people working at Foxconn:
https://truthout.org/articles/a-suicide-survivor-the-life-of-a-chinese-migrant-worker-at-foxconn/