Just do what we all do to dodge this, have the Account management and purchasing abilities sit inside an embedded browser window that opens up from a button push in the app. Yes it adds a little barrier but with Apple Pay it is a very small barrier and the juice is worth the squeeze.
They don't have to "cite the Epic case", it's just functionality available to everyone now. Your app is no longer blocked from approval for including an external payment provider.
They'd actually have to do it though and that could lead to a large loss of revenue for themselves and their subscribers.
In practice I’ve seen apps just game the system by (1) using IAP using the normal flow, and (2) giving user a button unrelated to purchasing that would open a new WebView, which just happens to contain a purchase button.
