Wear OS is set to get a new Android app from Google. This new app is in the offing, there are first hints in the Google Play services. The new app for Android smartphones has two different tasks, both of which have long been official.
This includes, for example, a better connection between smartphones and smartwatches. Google announces that you can unlock your smartphone with a smartwatch.
Pixel Watch: Google watch probably with its own app
But this app also has another purpose, as we can already find out today. It is also used to connect to the Google Pixel Watch. It is also clear that you can keep your smartphone unlocked with the Pixel Watch if both devices have a direct or active connection to each other. It also shows that the Pixel Watch doesn’t use the previous Wear OS app on the phone.
The rest is just speculative. There is currently no information other than the screenshot from 9to5Google. However, I would assume that the Pixel Watch can be used immediately with any Google Pixel without an additional app download because the necessary services are provided via Google Play Services.