Going forward we will only support django-oauth-toolkit. Additionally, we will move away from OpenID Connect in favor of OAuth 2.0 + JWT access tokens. We have had a proxy in production for quite sometime that provides the ability to issue JWT access tokens:
https://github.com/edx/edx-platform/blob/master/openedx/core/djangoapps/oauth_dispatch/views.py#L89-L90.
The exact timeframe for fully implementing these changes across all services/APIs is still to be decided. If you're planning to create a new API or service, use OAuth 2.0 + JWT. If you're attempting to integrate an existing service (e.g. ecommerce), please follow the appropriate guides (which still reference django-oauth2-provider).
Clinton Blackburn, Tech Lead
edX E-Commerce Engineering