Cloning an environment used to read from its last deployment rather than its current definition. If you cloned an environment that had never been deployed, the copy opened to an empty canvas, and the review step that lets you pick which values to carry over could be skipped entirely.
Cloning now reads the environment's current definition, the same one on the canvas. The copy matches the original whether or not it has been deployed, and the review step always appears, with sensitive values off by default.