Disagree. This feels more like the Google partnership with Apple' Safari that has lasted for long time. Except in this case, I think is OpenAI who will get the big checks.
This integration is way more limited and frictioned. Whereas with search Apple's fully outsourced and queries go straight to your 3rd-party default, Siri escalates to GPT only for certain queries and with one-off permissions. They seem to be calculating that their cross-app context, custom silicon, and privacy branding give them a still-worthwhile shot at winning the Assistant War. I think this is reasonable, especially if open source AI continues to keep pace with the frontier.
If Apple wasn't selling privacy, I'd assume the other way around. Or if anything, OpenAI would give the service out for free. There's a reason why ChatGPT became free to the public, GPT-4o moreover. It's obvious that OpenAI needs whatever data it can get its hands on to train GPT-5.
ChatGPT was free to the public because it was a toy for a conference. They didn't expect it to be popular because it was basically already available in Playground for months.
I think 4o is free because GPT3.5 was so relatively bad it means people are constantly claiming LLMs can't do things that 4 does just fine.