Stable Wear 4 emulators have landed. So update via Android Studio. Wear 3.5 emulators (ROW & China) also got a refresh. https://android-developers.googleblog.com/2023/10/wear-os-4-is-now-stable-and-available-on-google-pixel-watch-2.html

When will it land for the Pixel Watch?

I don't think a date has been announced, just that it's got the 3 years of guaranteed software updates, so hopefully soon.

Officially later this year, but should be in near future 🙂

Hopefully a bit before the Pixel Watch 2 is out, so people can upgrade, backup, then restore on the new watch, for the people that upgrade. That'd leverage Wear OS 4 backup, restore, and phone swapping capabilities I think.