It is is, but most of templating action happens in Ember's HTMLbars anyway.
And there's no telling how complete Jinja2 support is. From what I see all you can do is render templates via them, but there's no word on makemessages support in Jinja or interop, so primary reason for drop still stands IMHO.
edit: I've checked it and it turns out that in terms of Jinja2 support, Django 1.8 does less than other compat apps like Coffin, that gave you support for i18n, makemessages, as well as attempted to support Django's filters and tags in Jinja, so its no-go.