Probably an error, on the Verge it says:

With the launch of watchOS 26 next week, Apple will bring hypertension notifications, live translation, and the new wrist-flick gesture to the Watch Series 9 and newer, along with the last-gen Watch Ultra 2.

https://www.theverge.com/news/775200/apple-watch-series-9-hypertension-sleep-score-wrist-flick

If you always want the bleeding edge stuff, get on the Testflight. If you want only occasional updates with urgent fixes or thorough tested releases, the Appstore version is better suited. I used to use the Testflight but have since switched to the regular version and it is quite stable.