The details of the process of getting approval for links may be out of line, but the idea that simply using a different payment processor would remove the entirety of the 30% commission was always a pipe dream. Apple has always been adamant that the fee is for the service of using the App Store, not the payment processor, and that you owe them for sales made regardless of whether they're able to take the money directly out of your revenue stream.
That part of this outcome was inevitable, and I don't think any court will rule against it. It was even anticipated in the original ruling:
> First, and most significant, as discussed in the findings of facts, IAP is the method by which Apple collects its licensing fee from developers for the use of Apple’s intellectual property. Even in the absence of IAP, Apple could still charge a commission on developers. It would simply be more difficult for Apple to collect that commission.
That part of this outcome was inevitable, and I don't think any court will rule against it. It was even anticipated in the original ruling:
> First, and most significant, as discussed in the findings of facts, IAP is the method by which Apple collects its licensing fee from developers for the use of Apple’s intellectual property. Even in the absence of IAP, Apple could still charge a commission on developers. It would simply be more difficult for Apple to collect that commission.