It can be a useful rotation, but I would not teach it as something the 6 should always do.
If the centre-backs split and the opposition have left a player free to receive between them, the 6 dropping can create a useful overload.
The question is what happens to midfield after they leave it.
If nobody moves into that space, you may have four players building in your own third and nobody to connect with ahead.
I’d train the picture by letting the 6 choose whether to drop or stay, then review what each decision created.
At U13, players are ready to explore these relationships.
I just would not copy a movement because it appears in academy or professional football.
The rotation is useful when it solves the pressure in front of your players. If it creates a new problem, they need another answer.
