At the moment, Hubsot neglects the reality of the customer lifecycle, which includes the time after being a client / subscriber. The customer can, for various reason, cancel being a customer, if e.g. the business model is a subscription to a service or he chose to select products from a competitor.
What is missing then (goal) as a selection in the lifecycle phases is “cancelled”.
The value will be correct customer statistics including lists of cancelled customers and a lifecycle phase that should not interfere with the conversion rate (conversion rate untouched by changing phase from customer to cancelled).