This is nonsense. What you are telling us effectively creates double-class Canadian Citizens because they intend to leave overseas ?? It is a fundamental right of all Canadian Citizens, whether naturalized or born-Canadian, to come and go from Canada as they please. Therefore, IRCC cannot put your Citizenship application on hold because you intend to move out of Canada once you are granted Citizenship. Though, there was once a clause in the application, prior to 2015, that required aspiring Canadians to intend to reside in Canada upon Canadian Citizenship being granted. However, the Trudeau government repealed this requirement when he took office in 2015 because it violated the Charter of Rights and Freedoms.
Don’t believe everything you’re told.