If Taiwan doesn't fall completely in the first 48h or so, and the US feels ready for the conflict (which I'd expect them to if there's a war) what will happen is that they'll interdict shipping to and from China using anti-ship missiles, which will also make any naval landing difficult. So I expect China to either sucessfully land quickly (and thus, win) or not at all.
Also they'll most certainly bomb TSMC into the stone age, but I haven't seen evidence that this is, explicitly, part of the strategy.
There's also reason to believe that they'll get occupied Korea and Japan to help, but what exactly their role, other than providing weapons and munitions from their stockpiles, is unclear.