The other reason is that they want to repackage your app for different target systems. Right now they are stripping assets and native libraries, but I hear they

The other reason is that they want to repackage your app for different target systems. Right now they are stripping assets and native libraries, but I hear they are going to start precompiling dex and shipping OAT directly in the APK. I wonder if there's an internal fight between the Tools and Play teams, because all of this should be possible via the Gradle plugin, but understandably the Play team probably wouldn't see high adoption of APK splits if it required configuration via the morass of crap that is Gradle.