The Play Store has added visible user review history to all of the content which means that anyone and everyone can now see all of the reviews that a user has left about anything that's available to download from the Play Store. More specifically, if you leave a review about a particular app or game and then over time you edit that initial review, anyone else can see every single edit that's been made since the initial review was left and this includes the very first review. While this might not bother some people, others will surely care that everything they're saying is publicly visible.
If you're in the Play Store app on your mobile device, then tapping on the overflow button alongside a particular review will now have an option to view edit history which will take you to the entire history of all the edits that person has made about the content that you're looking at. This can be useful to others in the sense that it gives someone the ability to gain some insight into the possible history of how that content has worked or functioned over time. As useful reviews will tend to change based on how things were fixed or addressed by the developers.
For example, if something isn't working right and that is expressed by a user who downloads it, then it ends up getting fixed by developers in a pretty timely manner afterward, that user might update their review to include information that a fix was patched in rather quickly, which bodes well for user-support going forward and which could give future users peace of mind that developers are on top of issues. On the other side of things if a user is constantly editing their review and leaving bad comments, other users can see those things too, even if it ends up being changed to edit out anything negative. Whether or not Google plans to roll this out to the Google Play desktop webpage is unclear but it should visible to all users in the Play Store app at this point.