My son has been told to play quicker and now plays one-touch everything

I’d go back to the original feedback and make it more specific. “Play quicker” is easy for a player to hear as “use fewer touches”. If he is now playing one-touch even when he has space, he is trying to follow the instruction rather than read the game. I’d tell him directly that taking three touches can still be quick if they help him make the right decision. Then give him a better question: “How much time do you have?” Sometimes one touch is perfect. Sometimes he needs to receive, travel and wait for the next option. I would also praise examples where he uses extra touches well so he knows the coach really means it. At U13, feedback should create more choices, not remove them. If a phrase has narrowed his game, changing the phrase is part of good coaching.