Subscription metrics, which measure changes and trends in subscriptions, have been replaced with subscriber metrics, which measure changes and trends in your customers. This provides a better view into what is happening with your enterprise at the customer level. For example:
A customer with one subscription who cancels that subscription, comes back later, and subscribes to another subscription is now tracked as a reactivated subscriber. This reactivated subscriber now remains with its original cohort.
Churn is now calculated at the subscriber level, so a customer who has two active subscriptions would need to churn both in order to count as a churned subscriber
If most of your customers subscribe to only one subscription, this change is unlikely to significantly change your reported metrics.