With iOS 13, if you delete an app you've subscribed to, you'll get a prompt to also cancel the subscription. It's definitely a welcome change, but it could affect your subscription numbers a bit. David Barnard talks about the numbers he's seeing in this post. Hopefully, this will help curb some of the subscription abuse we see from shady developers.
Now, when you delete an app with an active subscription, iOS asks if you want to keep that subscription. ...apps that rely on customers forgetting to cancel a subscription will see the biggest change.
Apple’s New Subscription Management Prompt Seems to Be Working by David Barnard