Google is notifying certain app developers about an upcoming change to the way the Google Play Store distributes app updates (via Android Police). In the future, it seems pre-installed apps will have access to updates even if you haven’t signed in with a Google account.
When you first set up a new Android device, the pre-installed apps will be at the most recent version they were on when installed. To get the newest versions, you’ll have to sign in to the Google Play Store with a Google account. If you choose not to, the device won’t get any app updates at all.
Google is testing a new method which will allow pre-installed apps — including the Play Store itself — to get updates when a device is powered on and connected to the internet regardless if a user is signed in or not. In a message sent to some app developers with pre-installed apps on various devices or operating systems, Google says those apps in question should be updated to reflect this new policy change.
Google also explains in the message that this will only work for devices shipped with Android API version 21 or later (Android Jellybean, in other words).
To be clear, you still won’t be able to install new apps from the Play Store without signing in first. That policy won’t be changing — this will only affect pre-installed apps.
Google says it is just testing this new feature, but since it is asking third-party developers to update their apps, it’s likely this will be a permanent policy change at some point soon.