That is the problem. We keep perpetuating this by being worried and guarded. This is not a personal attack against you but all of us as a society and what that means. I have seen how PC talk can easily stop good, honest dialogue. I don’t intend for this post to turn in any way.
In a tongue in cheek way, when a kid wears a ninja shirt or princess outfit, do you see it as appropriating highly skilled martial artists or royalty appropriation. Back in the day, imitation was the sincerest form of flattery.
I think it is totally cool that the family wants to coordinate. It is one of the few Disney/Pixar movies where a family can coordinate like that.
As an aside, my wife read this book called iGen (https://www.amazon.com/iGen-Super-Connected-Rebellious-Happy-Adulthood/dp/1501151983) It was a really good read. We wished we had read it before our first daughter went off to college. In retrospect, it would have really helped to explain a lot of things and even one of our high schoolers read it, and thought it was spot on.