Do you ever coach a whole quarter in silence?

Yes, I think it can be a useful experiment. I would tell the players beforehand that you are deliberately going quiet, so they do not read your silence as annoyance. Then actually observe what changes. Who starts communicating? Who solves problems without looking over? Which situations genuinely needed help? Afterwards, ask the players what they noticed. I would not make silence a rule you have to follow if there is a safety issue or a player genuinely needs support. At U12, a quiet quarter can also be very useful feedback for the coach. You often discover how many instructions were not actually necessary. The point is not to prove that coaches should never speak. It is to create enough space for the players to show you what they can already manage themselves.