"Want to come to Canada" is not really a relevant example in this case, some of the people facing expulsion by this fascistic and ethnocentric policy have lived in Latvia for decades. It's explicitly being framed as a loyalty test.
People are citizens, permanent residents or people under some kind of implicit or explicit visa. The latter two categories are "granted", and the first category can be revoked for multiple-citizenships.
lol
Correction: you were meant to say British-French-Polish-German treaty of 30th September 1938, that provided "legal" grounds for the German, Polish, and Hungarian annexation of pieces of land of Czechoslovakia, preceded by the United Kingdom and France "informally" asking Czechoslovakia to cede its Sudetenland territory to Germany on 20th September, which was followed by Polish territorial demands brought on 21 September and Hungarian on 22th September.