These are basically honorary positions, and these people are overseas to start with, they don't draw government salaries, and they only come back to be consulted by the government. There is no reason to ask them to give up their foreign citizenship.
基本上他們都是榮譽職，本來就在國外，不拿政府薪水，只是開會時回來接受政府諮商，沒有理由叫他們放棄外國國籍。