Who cares about what rank you had when you were 10? Especially a rank where you don't remember anything you learned while earning it.
To be honest, I don't care what rank most people are. If you have skill or knowledge, or preferably both... thats what I care about. After that, I care about your ability to share that skill or knowledge. I don't really care what color thing you use to hold your pants up or who gave it to you. You either have the goods or you don't. They are not included with your belt.
One of the other things I don't personally care for... is folks "pulling rank" on each other. If thats your thing, why are you not part of the military? If you are not military, you just look kind of silly "pulling your rank" in front of people. I tend to find people to train with who can look beyond the belt or rank... at maybe the art.
But, if that will add to your resume... sure. I think its still valid. Most places go by once a rank, always that rank. So in a few years you can be 5th degree black belt, grand master in TKD and yellow belt in shotokan, when you were age 10.