Yes, it's true! It's been confirmed that Google is no longer counting anonymous reviews from “A Google User” in the total shown in the Knowledge Panel.
Although we are uncertain of the future of anonymous reviews, we do know many businesses will see an immediate drop in their review count. It will be more obvious to those that started the review process before the G+ era and have a lot of reviews from non-identified users.
The million dollar question: "Is this a good thing or a bad thing?" The answer is, "It depends". It could be a good thing if you were receiving negative reviews from random, anonymous stalkers, as these will be removed, and your Star rating should improve.
Click here to read the full article by Mike Blumenthal