I think you will find that Sonos, like many companies, very rarely ever mention their development roadmap, but I think you ‘may’ find that there are already some third-party Apps that cover at least part of the Sonos playback/control functionality on Apple Watch.

I’m personally not a user of that particular iOS device, so I’m sorry to say I cannot provide you with any suggestions, or recommendations, of Apps you can try, but perhaps start with an App Store search.