This seems like a consistent application of existing in-app purchase rules: purchasing a digital good to enjoy within the app requires IAP support for everyone else, so why not Coinbase? It's not clear (to me) that Apple is doubling down or strengthening the rules here.
If anything, I suspect that Coinbase intentionally violated the rules with this update so that it can sign on with Epic and Twitter in the fight against Apple.
If anything, I suspect that Coinbase intentionally violated the rules with this update so that it can sign on with Epic and Twitter in the fight against Apple.