No, we don't want to require everybody who sells an orange to pay for lab tests that determine for every vitamin how much is contained. Making such a requirement would be a death sentence for farmers markets.

A customers has certain expecations about what an natural orange happens to be. It's a class of objects that shares basic traits. GMO allows giving the orange traits that oranges generally aren't expected to have.

GMOing is a way of adding nutrients, but we would want additives labeled regardless of how they are added.

Any GMO interventions adds new molecules. If you follow that framework, if you add genes that produce 3 new proteins, put those three proteins on the label.