A new blue button on Control Center toggles Wi-Fi for extra control: 4.1 also expected to address Wi-Fi and cellular handoff issues.
Apple is planning to release WatchOS 4.1 at the end of the month. The update will be big: not only will it add music streaming over cellular and Wi-Fi via Apple Music and iCloud Music libraries and a new streaming Radio app, but it adds some fixes to address Wi-Fi and cellular issues acknowledged by Apple.
I've been using a preview of WatchOS 4.1, and I noticed the new blue Wi-Fi toggle button on my Apple Watch Series 3 with cellular. The toggle button is for added control, for when you might want to use cellular while a recognized Wi-Fi network is still in range.
The Wi-Fi control button was absent in previous versions of WatchOS, but only cellular models of Apple Watch Series 3 will have the feature. The watch still can't select specific Wi-Fi networks: the toggle just deactivates Wi-Fi altogether -- for the time being. If the watch comes back into contact with another recognized Wi-Fi network, the Wi-Fi will automatically toggle on again, as it does in iOS 11, unless you forget the Wi-Fi network on your iPhone.
We'll test connectivity more when the final version of WatchOS 4.1 arrives this month.
Apple Watch gets streaming music and radio: Hands-on with the new software in WatchOS 4.1.
Apple Watch Series 3 review: Full impressions and experiences with Apple's newest watch.