Edge VM deletion is blocked from the vCenter. User can't and shouldn't delete the Edge VM from VC.
Right click on Edge VM and you see "Remove from Inventory and Delete from Disk" Greyed out,
VMware NSX - versions 4.2.4 and above
VCF- 9.1 and above
This is a feature introduced in 4.2.4 and 9.1 onwards, that deliberately blocks the edge VM deletion and removal of the Edge VM from the vCenter inventory. As shown with the below image. This is to prevent the stale edge VM left on the NSX side, due to out-of-band deletion of an edge VM from vCenter.
If you believe you are hitting this issue, please open a support case with Broadcom Support.