We have a package listed on AppExchange that I am looking to upgrade. I deleted an unused Visualforce page from our package and created a "Managed - Released" package from this. We deleted this page because it is unused and uses an older SOAP API version. Will the Visualforce page be deleted from customer orgs if we push upgrade them? I was not able to find a clear answer to this online. When I tested this out it did delete the page, but this link seems to indicate it wouldn't delete the page.
Previously released VF pages aren't automatically deleted from subscriber orgs. After a VF page has been deleted by the developer and the new version of the packaged pushed (or installed by the subscriber admin) the admin in the org can delete the page from their org.
A couple of helpful links and the notes that are relevant here:
ISVForce Guide: Delete Components from First-Generation Managed Packages
Data and metadata are never deleted in a subscriber org without specific action by the customer. When a subscriber upgrades to the new package version, the deleted components are still available in the subscriber’s org. The components are displayed in the Unused Components section of the Package Details page.
This page also describes the 2-step process to remove dependencies between VF pages and components and apex and ensure future upgrades don't have problems.
ISVForce Guide: Components Available in Managed Packages
Component: Visualforce Page *2
2 If you remove this component type from a new version of your package, the administrator of the subscriber org can delete the component when a subscriber upgrades.