Yes, it's basically just like the do-not-track feature: we can only declare our intend, but we cannot be sure, whether or not this will be honoured on the serve

Yes, it's basically just like the do-not-track feature: we can only declare our intend, but we cannot be sure, whether or not this will be honoured on the server side of things. It would be up to Google to provide some kind of proof of legal relevance.