I just released some updates for this feature request.
- By default, all unreleased items will have their rating percentage hidden throughout the website (eventually official apps too).
- Global setting to display all ratings if you prefer the old behavior.
- Items without a release date won’t be hidden (to deal with old TV episodes and specials).
- Rating action still works on the summary page + apps.
As mentioned, the early ratings have virtually no impact on the overall rating once an item is actually released. However, hiding the ratings should help prevent some people from rating so easily and there is no visual benefit for them doing so.