That's true; that would be the better solution. Requesting a refund before deleting the app would give the user an error message telling them to delete it.

With the corner case that if the user no longer has access to a device with the app installed, they cannot get a refund.

If you lose the product you bought you can generally not get an refound ;=)

And doesn't apple have some form of remote logout/factory reset feature for lost devices?

EDIT: (Sure requiring remote factory reset for lost devices would not work if it's a iPad which has not internet connection and never gets one again in it's live time, but that would be an acceptable corner case I thing).

Of course they can.

If you no longer have access to a device you used to own, you should use findmy to remote wipe it.

If you really didn't want that, then you should at the very least go through the trouble of filing, with apple, that the device is lost or stolen, so that any attempt to return that device to an apple store or reseller to fix it gets it flagged.

It seems bizarre in the extreme that you'd want to somehow protect your privacy by not reporting your stolen stuff as stolen with apple, but that you opt in to a system where installing apps requires going through a single vendor.