The article says "internal version of the Uber rider app", which makes me think it's some sort of internal/beta/debug build of the app that everyone else gets. In that case it makes sense that many of the features would stay the same, including stuff like ads.

The “internal” app is essentially the same as the regular app. The difference is that it may receive beta features, there’s an easy “report bug” button and a side panel with diagnostics info, feature flags and other debugging tools.