From the release notes, it appears flask.cli may be intended to replace Flask-Script (4): "Added flask and the flask.cli module to start the local debug server

From the release notes, it appears flask.cli may be intended to replace Flask-Script (4): "Added flask and the flask.cli module to start the local debug server through the click CLI system. This is recommended over the old flask.run() method as it works faster and more reliable due to a different design and also replaces Flask-Script."