I guess I'm confused why its an existential threat to have Chatgpt/Anthropic/etc branding on an Apple device. Alphabet/Meta products both appear on iPhones and use their own branding. I guess it would be unprecedented for Apple to allow an external partner that deep into their walled garden and replace Siri, but I don't see total vertical integration as a plausible outcome for Apple. I think they would waste a bunch of money and then lose!