Language fallback for unpublished translation on our Drupal 7, we have pages in 6 different languages. We'd like to remove the translation for some nodes. 

I thought that users would be automatically redirected to the default (English) language when trying to access this unpublished translation, but this is not the case, they have a "not found" page.

I installed the language fallback module and configured all languages to fallback to English, but this did not help.

Is there something else I can do so that all traffic to unpublished translations is redirected to the default node translation ?
I never used it, but this module seems correspond to your problem https://www.drupal.org/project/multilink