The Republic of China flag emoji has disappeared from Apple iPhone’s keyboard for Hong Kong and Macau users. The change happened for users who updated their phones to the latest operating system.

Updating iPhones to iOS 13.1.1 or above caused the flag emoji to disappear from the emoji keyboard. The flag, commonly used by users to denote Taiwan, can still be displayed by typing “Taiwan” in English, and choosing the flag in prediction candidates.
— Read on www.hongkongfp.com/2019/10/05/taiwan-flag-emoji-disappears-latest-apple-iphone-keyboard/