The reason behind sending the notification is to combat the apps that snoop on user data. The action will affect the fake apps that are created for the sole purpose of stealing user data. Such apps will face the major jolt of the cleansing drive executed by Google. For the ones who will avoid the notice and make no changes to their app's functionality - their app will be removed from Google Play Store.
Here's the screenshot of the warning message:
Commenting on the cleansing drive by Google, Hip Hop Ninja app developer, Jack Cooney told The Next Web:
I think it’s fantastic, this will clear the Google Play store of so many junk and zombie apps that our games will find increased visibility on the store as the search terms will become much less cluttered.
This will make it easier for people to be able to find our app’s like Hop Hop Ninja! with better keyword searches like ninja or Nerd Agency and find much more relevant results. (A previous pain point of developing for Android).