I'm not sure your logic connects. With respect to "OpenAI being boxed out from [Siri]", advertisement revenue comes neither too late nor too early. Whether or not OpenAI had advertising would not have substantially affected Apple's decision to go with Google's LLM at this time.
If you meant it in a different context, you didn't explain any of the actual context you had in mind.
My question is why anyone would continue to use OpenAI to look things up when existing "default" apps like Google search on Android and Siri on iphone will have excellent AI powered search.
Certainly, for indepth questions like writing term papers, someone might fire up OAI, but that doesnt automatically seem like as giant a moneymaker as simply being the fall-off-the-log easy choice for search.
If you meant it in a different context, you didn't explain any of the actual context you had in mind.