Apple has released a preview of new features in MacOS 12 Monterey, which will be issued in the fall of 2021. Below are the parts that relate to languages.
+New keyboard layouts: Ainu, Amharic, Fula (Adlam), Igbo, Navajo, Rohingya, Syriac, and Tigrinya
+New Voice Control languages, including Mandarin Chinese (China mainland), Cantonese (Hong Kong), French (France), and German (Germany).
+New dictionaries for India, including Urdu–English, Tamil–English, Telugu–English, and Gujarati–English.
+New Simplified Chinese idiom dictionary for China mainland
+New dictionaries for Hong Kong, including a Traditional Chinese–English idiom dictionary, a Traditional Chinese–English dictionary of Cantonese colloquialisms, and a new Traditional Chinese dictionary.
+Dialect lexicon support for Cantonese and Shanghainese: Type words in Pinyin using native Cantonese or Shanghainese dialectal spellings.
+On-device dictation, available in Arabic (Saudi Arabia), Cantonese (Hong Kong), English (Australia, Canada, India, Singapore, UK, U.S.), French (France), German (Germany), Italian (Italy), Japanese (Japan), Korean (Korea), Mandarin Chinese (China mainland, Taiwan), Russian (Russia), Spanish (Mexico, Spain, U.S.), Turkish (Turkey), and Yue Chinese (China mainland)*.
+Neural text-to-speech voice in more languages: Swedish (Sweden), Danish (Denmark), Norwegian (Norway), and Finnish (Finland)*.
+Mixed English and Indic language support in Siri for Hindi, Telugu, Kannada, Marathi, Tamil, Bengali, Gujarati, Malayalam, and Punjabi.
*Requires Mac with M1 chip