Apple briefly proposed something similar but then reversed course pretty quickly and has unequivocally stated that it was a poorly thought out idea when they proposed it.

I'd have to assume that Apple and WhatsApp are taking a more behind the scenes approach on this and that they too would leave the EU if it came to it. Both of their messenger brands are so fundamentally tied to E2EE that its hard to imagine them thinking its worth it to stay and break their encryption.

Assume the worst. Everything Apple does is proprietary and closed, so you can never be sure. You paid for the device, but it's not yours.