IMO, China will not be able to hold Taiwan for long, even she takes it. It was colonized by mostly Fujianese & then lost to mainland rebels, Dutch, & Japanese before the KMT fled there.
Historically, & in the long run, attackers from the West & South always lost all wars: Japan was unsuccessfully invaded twice by the Mongols; Korea was invaded by Japan/US, but China came from the North & retook all/1/2 of it, respectively. The Mongols took C/S Asia, China, ME, & Russia; US lost in Canada in 1812 but took 1/2 of Mexico, Hawaii, Philippines, Guam, finally defeating & occupying Japan in 1945.
China will have more luck taking underpopulated SE Asia & later Australia.