Link existing B2C tenant via Azure CLI

How to link an existing B2C tenant programatically via Azure CLI? Running this line:

az resource create --resource-group <rg> --resource-type Microsoft.AzureActiveDirectory/b2cDirectories --name <tenant>.onmicrosoft.com --location Europe --properties "{\"tenantId\": \"<tenantId>\", \"sku\": { \"name\": \"Standard\", \"tier\": \"A0\" } }"

Returns BadRequestError: The 'sku' property is required for creating a b2c directory resource but it is there

The ARM "B2C Link Resource" looks like this:

{
   "type": "Microsoft.AzureActiveDirectory/b2cDirectories",
   "apiVersion": "2017-01-30",
   "name": "[parameters('name')]",
   "location": "[parameters('location')]",
   "tags": {},
   "sku": {
      "name": "Standard",
      "tier": "A0"
   },
   "properties": {
      "tenantId": "[parameters('tenantId')]"
   }
}

Further Information:

• I have tried different variations regarding the sku portion such as leaving it out completely or moving it as a dedicated parameter --sku Standard etc but none of them seem to work
• Removing an existing link via az resource delete --ids /subscriptions/<subscriptionId>/resourceGroups/<rg>/providers/Microsoft.AzureActiveDirectory/b2cDirectories/<tenant>.onmicrosoft.com works perfectly fine
• Why do we need this? We automate our infra deployment with Terraform. We're aware of the limitations automating B2C tenants (see here, here or here) so we aim for removing/adding the b2c link via pipeline to at least keep the subscription clean on destroying/applying infra.
• Linking an existing B2C tenant via Azure Portal looks like this

Any advice appreciated. Thanks for your help!