That wasn't clear in the article. However as others noted: It's also been removed from their list of purchased apps, so if their iphone gets damaged, or it gets deleted from their phone due to a mishap, they're still out the cash they paid and left with empty hands.

> Are you saying that Apple shouldn't let developers stop selling an app?

They should do the same thing Steam does: Remove the store page and keep it available for redownload by customers who paid until it positively cannot function anymore.