Assign of a license to the tanzu supervisor asset usually occurs via the menu
You may not be able to select the license and click remove ( remove will be unavailable or greyed out )
Adding a new license to the Licenses may still not allow you remove the expired license.
Removing the Tanzu workload management cluster may still have this issue afterwards if looking to recycle a license.
Furthermore you may find under Assets
You may not be able to Assign License
vSphere with Tanzu 7.x
vSphere with Tanzu 8.x
The license used by the supervisor asset in vSphere version 7 causes this issue.
The issue is solved in vCenter version 8 onwards and only occurs on vCenters that have updated from 7 to 8.
Please open a case with Broadcom support if you encounter this issue.