Beside semiconductor, there are a lot of things that China still import a lot like Helium gas, high grade chemical, etc. I don't say China cant produce them, but if USA blocked all China need, China will suffer a lot too.China can play the rare earth metals card but might be too premature giving election is around the corner. IMO it's also not in China's interest to further heighten tensions given that the Trump administration might be on it's last leg and inflaming tensions could play into Trump's hand of distracting the election process and focus.
Targeting U.S. companies is counterproductive because these companies are already under a lot of fire from the Trump administration for doing business in China. If China singles out U.S. tech companies and punishes them when they have done nothing wrong, then you are giving them incentive to move away.
It should be the other way around IMO, where China tries to draw more business from U.S. companies, especially after many of these companies lost profits from COVID. Tensions with China are already worrying many U.S. companies because it could mean lost profits. Let the U.S. firms figure it out with Trump.
Better give them asymetrical ban, like banning GM and Ford, they will bankrupt without China.