This article covers
What is an IPN notification?
When does Paypal billing ID get removed
Customer canceled billing agreement ID
In Chargebee, the Billing Agreement does not expire unless your customer cancels it. Therefore, it's not ideal to send an Update Payment Method link automatically as businesses have a different approach to handle such instances.
So, in such scenarios, when your customer has canceled the Billing Agreement in their PayPal account it is notified as an IPN message.
Chargebee will receive this message via a notification URL
Chargebee removes the corresponding billing agreement automatically (GDPR compliance)and notifies the Admins and Owners of your Chargebee account.
At this stage, you can choose to ask your customers to update their payment method.
However, Chargebee sends out automated emails to notify your customer on renewals, when the system identifies no payment via Online Dunning. Chargebee automatically sends emails to your customers to "Update their Payment Method".
On the other hand, emails being sent to multiple users of your Chargebee account is not an ideal way as there are people from different hierarchy levels involved.
Contact support to know more.
Related articles and Documentation
What is the billing agreement for PayPal Express Checkout?
Is it mandatory to provide Chargebee's URL for IPN notifications while configuring PayPal?