Since the article doesn't actually repeat what Apple has said, here's what Apple says: == Begin quote == The iOS system has traditionally provided support for Home Screen web apps by building directly on WebKit and its security architecture. That integration means Home Screen web apps are managed to align with the security and privacy model for native apps on iOS, including isolation of storage and enforcement of sys…
> malicious web apps could read data from other web apps and recapture their permissions to gain access to a user’s camera, microphone or location without a user’s consent. How is this even possible? It's shocking that these APIs even exist for any browser to use.
Apple could add a bunch of new APIs to support this case for third-party browsers. Presumably there's something equivalent that's being done for said web apps currently in Safari. But they're not wrong to say that there's not an existing system in place that said third-party browsers are already written to use. (And, you know, they're clearly not invested in trying to make this law succeed.)