Get this screen when you try to update your watch? Here’s a trick. 
Jason Cipriani/ZDNETEvery month, Google releases an update to its Pixel phones and the Pixel Watch. Typically, the update for the Pixel phones is available within an hour or two of the news going out — no special tricks required. 
Updating the Pixel Watch, however, requires a bit of patience while you wait for the update to reach your watch. But, you don’t have to wait. As soon as the update is available, you can force your watch to download and install it with an annoyingly simple trick: Tapping on the update screen over and over. 

Also: Google’s Pixel Watch can now detect if you fall: How to turn it on
I was reminded of the shortcut that used to work on old Wear OS watches by Droid Life shortly after the Pixel Watch launched, but forgot all about it until Monday when the April Pixel Watch update was released. 
So, this morning, I checked for an update on my Pixel Watch and after nothing was found, I started tapping. Thirty seconds later, my watch was downloading the latest update. Magic.
If you’re tired of waiting for each update, here’s what you need to do. 
How to simply update your Pixel Watch Open the Settings app on your Pixel Watch by swiping down from the top of the screen and selecting the Settings gear icon. Next, scroll to the bottom of the list and select System. Select System updates.
Your watch will take a second to check for available updates. If nothing is found, you’ll see a screen that says your watch is up to date. Don’t leave this screen!

Jason Cipriani/ZDNET Here comes the annoying part: Start repeatedly tapping the screen, and don’t stop until the screen refreshes and the update starts to download. 
This trick worked for me on the first try this morning. I’d say you can stop tapping around a sixty-seconds. At that point, it’s safe to assume the update hasn’t fully rolled out yet. 

This is the kind of “hack” that really makes you scratch your head. If forcing the watch to download an update is only a few (OK, a hundred?) taps away, why not just let the watch find the update right away? 
Either way, I’m glad it works.

Latest news
https://www.zdnet.com/article/force-pixel-watch-to-download-the-latest-update/