[Answered ]-Strings from default locale missing from Django JavaScript catalog

This was identified as a bug in issue #33863 and a fix was submitted. The solution will be to update Django when this fix is released.

As a workaround, I suggest what I noted in the question (pass packages to JavaScriptCatalog):

path(
    'jsi18n/',
    JavaScriptCatalog.as_view(packages=["<your-app-here>"]),
    name='javascript-catalog'
)