That’s very possible. The only point of the above map and Okinawa comparison is to point out what would be possible IF fierce resistance was given.
In one year or less, Taiwan could have mass-produced state of the art ATGMs, MANPADs, sniper rifles, drones, advanced mine systems, prepared every bridge and tunnel with demo (as in Switzerland) etc etc.
Inert trainers for the above can also be mass-produced and everybody on the island would be familiar with them, along with video training.
IF the will is there, the island can be turned into a fortress.
Personally, I think Taiwan’s billionaires will cut a deal with the CCP and sell out the people.
It’s possible that China will propose an arrangement like Hong Kong 1997, but once China has its people in place on the island, if China violates such an agreement, there is no way to force China to keep its word.