No one is alleging copyright violations. The claim is that they violated OpenAI's terms of service. We don't know whether Google ever even agreed to those terms of service in the first place.
Services are subject to terms of service. (If content is received through a service, the terms of service may govern use of it, but that’s not a feature of the content, but the acquisition route.)
The only claim being made against Google here is that they used ChatGPT content. I can't find any sources claiming that Google made use of an OpenAI service. So the distinction is correct, but doesn't seem particularly valuable in this context -- using data from ShareGPT is not a TOS violation.
> that’s not a feature of the content, but the acquisition route.
It's neither. It's a feature of contract law.