Yes, with that system, diecutter depends on Jinja2 and Django.
That's ok for a first iteration. There are only 2 external engines. The current priority is to be able to use Django templates and to have a proof-of-concept implementation of "diecutter supports several template engines".

Yes, it would be better to have template engines implemented in external projects, so that diecutter itself does not depend on every template engine library in the world :)
This may become important... later! As an example, when we want to add a 3rd template engine, we will consider an alternative. Also, if Jinja2 or Django engines become a bit more complex, then they may be moved in separate projects.

As a summary, let's depend on both Django and Jinja2 for now... And improve later, whenever we can or need to.