In China and Japan, a copy is just as good as an original

This blew my mind coming to Japan for the first time, coming from a European country full of castle ruins people have decided to keep in-tact, not restore - similar to the Ise Grand Shrine described in OP's article, most 'old' castles around Japan are relatively new.

Kagoshima Castle was built in 1601, but burned down several times since. Kumamoto Castle was rebuilt in concrete in 1960. It's hard to say whether these are copies, the attention to rebuilding is painstaking. Kumamoto Castle suffered heavily in the last earthquake and is still closed. I saw a documentary on how they used old pictures of the stone pile walls to number the stones on the ground, so that they could pile them back up (replacing some) exactly the way they were piled up before...