What more concerning than the lawsuit is they have all the money in the world and can’t execute on getting Siri working right. That is not a good predictor for how well engineering is at Apple. :/
Then again it's very possible they are just flailing. I don't have strong beliefs either way.
Apple won't ever allow anyone else to own and control their core technologies (as we saw with Google Maps back in the day). We can safely assume their deal with Gemini is for Google to sell them a model-as-a-service component that can be swapped out at any moment, with either another model like Claude, or with Apple's own future models.