When i go via the search engine, I can see all of my reviews on all 3 listings have now been labelled GROUP TRIP whether 2 people or 10 people stayed. If you are saying the review would appear on all guests profiles, that makes the assumption that the person booking has also entered details of the other guests and they have airbnb profiles. I know most of mine are families where the person booking is the only one with an Airbnb profile. So what would be the purpose of this label? I would understand if it was for say more than 8 people so guests could see it caters for groups.