As of now ([email protected]) that’s right, however, user management will come very soon (but not include support for external identity services in the first release).
I don’t have first hand experience with AWS Cognito but have used n8n behind basic auth configured by Nginx rather than n8n. So your approach sounds perfectly fine to me. Keep in mind though that everyone with access to your instance would be able to see all workflows and credentials. So as per the linked post you’d need to ensure to spin up separate n8n instances per user if that’s not desired.