From the article you linked: "Back in March, WeChat banned Uber, a significant channel for how Uber communicates with customers."
The most that WeChat could do is (i) stop Uber from sending messages/promotions to people subscribed to Uber's WeChat account, and (ii) stop uber.com URLs from being displayed in the built-in browser.
Neither of these would affect customers' ability to (i) download the Uber app, (ii) book Uber rides.