Sounds like something Apple should fix. They know you have a subscription for the App you're deleting. They should ask
"You have a subscription for this app's services through Apple Pay. Do you want to unsubscribe?"
They could even say something like
"You have a subscription for this app's services through Apple Pay. Do you want to unsubscribe? Note that this app is still installed on your iPad" (assuming you deleted it from your iphone)
As a tangent I notice that while Apple's hardware and OS are best in class their support infrastructure is arguably close to worst in class. Every time I have to deal with their support and order systems (apple.com) I run into issues that make it almost seem like they're still doing everything on paper and that none of their systems are connected.
"You have a subscription for this app's services through Apple Pay. Do you want to unsubscribe?"
They could even say something like
"You have a subscription for this app's services through Apple Pay. Do you want to unsubscribe? Note that this app is still installed on your iPad" (assuming you deleted it from your iphone)
As a tangent I notice that while Apple's hardware and OS are best in class their support infrastructure is arguably close to worst in class. Every time I have to deal with their support and order systems (apple.com) I run into issues that make it almost seem like they're still doing everything on paper and that none of their systems are connected.