The automatic initiation of "Registers the BillingBenefits Resource Provider" should not affect your ability to cancel your Azure subscription. This process is part of Azure's resource provider registration, which configures your subscription to work with specific services.
To prevent this function from initiating, you can manually unregister the resource provider using Azure CLI or PowerShell:
Azure CLI:
bash
az provider unregister --namespace Microsoft.Billing
PowerShell:
powershell
Unregister-AzResourceProvider -ProviderNamespace Microsoft.Billing
Ensure no resources from this provider are in use before unregistering.