@Gianluca26
I don't think you have understood. This isn't a loophole and it's nothing new. A host or guest has always been able to ask for the review they wrote to be removed. At least, I have known this for a few years, so it's definitely not a new policy and there's nothing to be 'solved'.
Just the other day, a review/ratings from a recent guest were removed, but only because the guest herself requested it. I spoke to several Airbnb CS reps about this particular review and all of them told me the same thing, i.e. that they could not remove the review on my request. The author (guest) must request it:
So, again, it's not a loophole, nor a trick. It's policy and has been for a while.
It does not make any difference if you are asking for someone else's review to be removed. In that case, the review has to violate Airbnb's review or content policy. There's no way around that.