Hello @Phong Pham Thanh,

This changeset involves the Paracel Islands, which are disputed territories. Disputed territories usually labeled in the language of the country that actually controls the territory; information about territorial disputes is typically noted in administrative relations and tags.

Paracel Islands are currently under the actual control of China. Therefore, elements on them should be labeled primarily in Chinese. 

Therefore, I will restore some of the damaged data because OSM follows the “de facto” principle. If you still have questions, feel free to communicate.

Sincerely, @Rukkhadevata