I think it's such a cool thing. I know it's a weird thing to say, but such a great commonality. You hear of kids all over the world 6-7ing each other.
My kid is graduating. She was at an elementary school reunion at her elementary school. As I was walking away from school after the formalities, I saw her with friends, walking to one of her old classrooms. An elementary kid jumped out of another classroom and 6-7'd them. She and her friends did it back and you could hear the whole classroom of kids screaming. She said that the same thing happened with her friend when her friend did her elementary school reunion thing.
If that's all young people have that they can bond with any other kid, anywhere, then I'm all for it.