After Clearing all Edge SWG (ProxySG) policy via CLI, unable to remove IWA-BCAAA or IWA-DIRECT.
Once Edge SWG (ProxySG) has been removed from the Production, Even though no users are using Edge SWG (ProxySG), there is compiled version of policy still loaded on the RAM. You have to wait 10-15 minutes more so that there is no user traffic on the proxy and all pre-existing established connections are cleared.
To allow the admin to delete IWA-BCAAA or IWA-DIRECT realm you would either have to wait 10-15 minutes and/or reboot the Edge SWG (ProxySG) before the realms can be deleted.