The Google Play Store has undergone several changes in how it displays app reviews in the past year. Almost every app on the Play Store is guilty of prompting its users to leave a five-star rating on more than one occasion. One can't necessarily blame the developers, as a good rating helps the app's ranking on the Play Store. One of the major grouse users have with it is that the rating system forces one to navigate away from the app into the Play Store. Now, it isn't that much of an inconvenience, but a lot of users find it annoying nonetheless. That could now change in the future, according to an APK teardown by XDA Developers.
The teardown was performed on version 15.9.21 of the Play Store app. It is a beta build and is rolling out for users who have enrolled for the Play Store beta program. The folks over at XDA stumbled upon an activity which suggests that a user will be allowed to rate an app without leaving the app. The feature doesn't seem to be implemented just yet and may find its way in a future build of the Play Store.
There is a possibility that the developers might use the feature to generate fake reviews when a user isn't looking. Android Q has safeguards in place that can prevent such a thing from happening, so we may likely have to wait till Android Q is released officially before the feature goes live. Google could also test it out in a future build of the Android Q beta. Similarly, Google will have to put in additional mechanisms to detect auto-generated reviews on an app's Play Store listing.
In the past, some scummy apps have been known to solicit five-star reviews from users by promising them some free stuff in return. There is no way for an app to know what rating you left for it, but a lot of people don't know any better and leave a good rating for an otherwise scammy app. It is highly doubtful that an app will know the nature of a review left by the user with the new rating system in place, but it'll still open up opportunities for shady developers to eke out positive ratings out of gullible users.