Oh honey, no one is telling children they're trans. Trust me. Everyone is telling children that they're cis, repeatedly, hard, insistently, like a chorus of total negation. If a kid manages to figure out that they're trans in spite of every fucking thing in the world telling them they aren't trans, it wasn't because someone told them they were trans. The most they likely ever heard, and it's not all that likely, is that it's okay to be trans.
But you know that already. You don't want anyone to stop telling children they're trans, because no one does that. What you want is for it not to be okay to be trans.