If a WHMCS admin terminates an Enhance hosted website, the customer is not deleted nor is his/her package removed.
I imagine the same holds for auto-cancelled websites too but I haven't tested it yet. I assume so because generally the same function in the module serves both.
The problem is that if the customer can still login, he/she can still create a website without being charged. At the very least the package associated with the hosting should be removed too.
Would be nice if a customer without any remaining website or package would be removed too, but I get that will create orphaned data within WHMCS unless the orgid field is removed from WHMCS as well. It would aid cleaning up no longer needed customers from the Enhance database and the UI list of customers.