Although, that of course won’t happen until the feature is officially available. To be more clear, the update does indeed appear to include support for Google Assistant. But right now, according to DroidLife the feature is nowhere to be found even after the watch has been updated to the latest software. This would suggest that Google has to enable things server side. And if that’s the case, then there’s still a little bit of a wait to be had. What might be happening here is that Google has yet to publish the Assistant app for watches to the Play Store.
You will need to download Google Assistant to your Galaxy Watch 4
In Verizon’s software update support post, it says users will need to download Google Assistant. The post also notes that users will be able to see the Google Assistant feature within the settings menu. And that it should be listed under Google accounts. Since it doesn’t appear to be there even after the watch has been updated, you almost certainly need to download the app first. The only problem is that it’s not available in the Play Store right now. So Google probably hasn’t published it to the Play Store yet. Once it does, users should be able to see the options in settings. Then move on to being able to set things up. Worth pointing out is that this may be an update that’s only available for the Verizon version of the watches. Seeing as we don’t have the update on our non-Verizon watch yet, this seems like a reasonable assumption. As for the version you’re looking for, it should be R885USQU1FVC8 if you’re on the 42mm of the Classic, and R855USQU1FVC8 if you’re on the 46mm. The non-classic models have a similar version number. Albeit with 85 and 95 being swapped out for 65 and 75 in the version number respectively.
Update: April 20, 2022 According to 9To5Google, Samsung has confirmed that the update does not include Google Assistant rolling out for watches. Which means users won’t have access to it yet unfortunately.