I'm not 100% sure that the en-GB will remain intact after core update because it's still a default folder and developers can do whatever.
But you can create a Canada package easily. First, duplicate the en-GB folder and rename it as en-Canada. Second, change the ìnformation in the metadata.json file. Third, copy all files in /qa-include/lang folder into your /qa-lang/en-Canada.
Now you can edit your email preferences.
If new Q2A update has new language elements, just add what is missing.
If you don't add, the language will be English, not Canadian.
(Of course Canadian language here is just psuedo)