The current merge scripts are not ready to replace quite yet. The other changes in this bug make this dance with shipped-locales unnecessary. The calendar shipped-locales file does not require changes in comm-central so that's why there is no update for it as is the case for c-c.
Bug 1632986 Comment 2 Edit History
Note: The actual edited comment in the bug view page will always show the original commenter’s name and original timestamp.
The current merge scripts are not ready to replace quite yet. The other changes in this bug make this dance with shipped-locales unnecessary. The calendar shipped-locales file does not require changes in comm-central so that's why there is no update for it as is the case for mail.