Prior to May 23rd, 2018 there were numerous reviews from an anonymous source, which, really, was any user that wanted to leave a review but was not wanting to be “Put out there” and thus stayed anonymous by using the “A Google user” as their review tag. After May 23rd, 2018, Google removed a large number of these reviews which sent the review ratings of many people and companies down because of the removed reviews.
The removal of these reviews seems to be a permanent act by Google, not an error.
It is unlikely that these anonymous reviews will ever return due to Google trying to reduce spam.
Depending on what the reviews said, this could be a positive or negative thing for the businesses affected.
“Reviews designated by this language came from a variety of scenarios, but are chiefly fallout from Google’s rollout of Google+ and then its subsequent detachment from local.”