There's tons of "content" on the web that's duplicated. Privacy policies, terms of service, shipping policies, return policies... all those "legalese" pages are going to be substantially similar for large numbers of sites.
Google will not penalize you for these. They just won't. They're smart people and they understand there are only so many ways you can say "this site collects cookies" or "we process orders within 24 hours" or "returns require a Return Material Authorization number".
Instead of blindly running around in a panic because of what some so-called "expert" declared, let's stop and think for ourselves for a minute, shall we?
Since Google requires you to have the policy in order to run Adsense ads, blocking it so they can't tell you're complying with their rules doesn't seem like a very good idea, does it?
And since they require you to have the policy, and they even tell you what information needs to be in it, and point you to a resource to help you write the policy, they're bound to know that most policies out there will be substantially the same, right?
So what this "expert" is saying is that Google has told you to write a policy, pointed you to a resource to help you write it, thereby practically guaranteeing that most such policies out there are the same or very nearly so -- and then they're going to turn around and penalize sites for doing exactly what they require you to do, unless you hide the policy from them, thereby making it harder and more labor intensive for them to verify you've actually put the policy in place to start with.