If you rename a Calculated Metric, Adobe will:
- duplicate the old metric,
- apply the new name to the duplicated metric, and
- continue to use the old metric with any report that uses it.
The correct behaviour should be: Adobe will:
- keep the metric,
- apply the new name to that metric, and
- use the new name in any report that uses that metric.
I'm surprised that no one has discovered nor fixed this bug.