I'm gonna have to disagree with you on this one. Next-gen Google Assistant for Wear OS3 is likely to be one of the big selling points of the Pixel Watch. Google is going to want to be the first to showcase its improved assistant on its shiny new Pixel Watch. They aren't going to let Samsung steal their thunder on this one.That would be a very stupid move of Google which would sabotage the broader acceptance of Wear OS 3. So I don't consider it likely.
Google wants more Wear OS 3 market share ASAP. So they won't hold anything back artificially what many people are loudly requesting already now.