I think that what OpenAI is getting in return is their brand name being featured prominently in one of the top selling smartphone brands in the world.

The other wildcard here is that OpenAI will likely exit in some way, most likely by acquisition. Who knows, maybe Apple would buy them.

If I were to defend OpenAI's decision to work with Apple, I would say that Apple's ability to do gap analysis won't necessarily help them catch up with OpenAI's capabilities. If this was the case, Apple would have figured out how to make a better modem than Qualcomm by now.