The project has indeed been analyzed recently (less than an hour ago).
If it has been fixed in newer versions of SQ I’ll try and apply some gentle pressure on the team that is responsible for updating our SQ instance.
SONARJAVA-4908 refers to type patterns, while my example uses an Enum. I cannot tell for certain if that case is also addressed in the referenced issue.
I was also looking at another issue with similar switch statements about rule Java:S1301.
Reports some issues with switch statements using type patterns, among which the aforementioned SONARJAVA-4908. Similarly to this issue SONARJAVA-4904 applies to Java:S1301 for type patterns. Perhaps in general Enum patterns were overlooked? Many of the same logic about exhaustiveness applies.