In that specific case there was already an exception for "reader apps" where the user was already subscribed elsewhere and is merely using the app to access con

In that specific case there was already an exception for "reader apps" where the user was already subscribed elsewhere and is merely using the app to access content they've previously purchased. Where I suspect this would apply is apps like Fortnite, where if you were previously selling V-bucks directly via IAP, then popping up a web view to process the payment and returning you to the app to claim your V-bucks might not actually be the loophole people seem to think it is.