A nice new feature for developers: You're now able to have different changelogs for production, beta and alpha versions of your app. Before it was all or nothing — and nobody wants to see a new changelog for an app without an update. We'll definitely take advantage of this with our next version, which should be available as soon as it's ready. (See what we did there?)
From the Google Play Developer dashboard announcement:
“What’s New” now configurable for each version of your app You can now configure the “What’s New” section of your Store Listing for each APK that’s published, including Alpha, Beta, and Production. To get you started, we’ve automatically imported your existing Recent changes text for all versions of your app.
Source: Google Play support