But the norms for Masses with Children allow changes to be made to the liturgy for pastoral reasons: eg the use of gestures, different music, simplified texts, fewer or shorter readings, simplified language, a Eucharist prayer for children.
Also, children can be dismissed from the body of the Church during the Liturgy of the Word, and so the word is read and preached to them in a more experiential way by non-ordained lay people. This would presuppose that Children are to be treated differently since they are different. I would imagine that no Bishop is going to chastise a priest for taking the gospel book to the children during a children’s liturgy.