It's basically saying the same thing. One thing other apps can't do on iOS is... installing packages on the system. This is only a thing that the App Store app can do. So Apple has to open up to third party the possibility to install packages on the device, exactly how on Android any third party can install apps on the device.

By the way, this will impact Android too, since there are permissions that are limited only to Google applications such as the Google Play Services, that (interpreting this rule) now shall be opened to any apps that require them.