China is working to escape middle income trap, their goal is to shift into higher paying domestic consumption + services which means inevitably shifting manufacturing out of the country. They are already experiencing labor shortages due to high wage, and combined with efforts to reduce pollution the government and business owner interest are aligned. Keep in mind most of the factories Chinese owned, they have incentive to offshore their business to where labor is cheap, currently that's in adjacent ASEAN countries that's relatively close to Chinese logistics chain.
As for Africa, they're already paying for the infrastructure, if resources is near by, it makes sense to consolidate manufacturing. And geopolitical it's preferable to boosting the development of India, an immediate regional competitor. Also Africa is fragmented and easier to negotiate with, have similar demographics to India (lots of young), more willing to learn mandarin. Alternatively, we're not even sure if massive manufacturing nations are viable with automation. Regardless there's
curious, what do you mean by that?
"China will spin up African manufacturing"
you think that will work? also, my limited understanding is that china is after africa's natural resources, infrastructure etc, not people.