If an inappropriate review is removed by Google Play, is its associated rating also deleted? Say a user leaves a hateful review on an app with a ★☆☆☆☆ rating. If the developer reports it as inappropriate, Google may remove it as explained here.

Does this only hide the review message, or is the rating also get deleted (so it doesn't weight on the app average rating)?
It doesn't delete it unless Google Play Review Team reviews that review and then deletes it including its rating if it doesn't follow Google Play Comment Posting Policy.

You can report a review either through Google Play Console or Play Store itself.

If you report through Google Play Console, you will be able to report it only once. If Google rejects it, you can't report it again.

If you report through Play Store, it will be hidden only for you, while it is still visible to all other users. If it is not deleted and Google rejects your report, the review will be visible to you again usually after a couple of hours, and the rating will still be counted, but you will still be able to report it again although Google will mostly reject it again and again.

However, in most cases according to my experience when I review 1-star reviews with hateful⁽¹⁾ comments, they don't get deleted. Google is very strict about reviews. They sometimes even delete real 5-star reviews and keep hateful 1-star reviews undeleted. That's frustrating I know. The only 1-star reviews that got deleted were those that were totally irrelevant to the app that promoted a service or another app or simply looked like an ad.


(1) By saying the word "hateful", I mean comments that curse or promote violence.