He wouldn't even need to do that. He could literally just make a third account (assuming his daughter is blocking the one where Elon pretends to be an actual child) and see all the posts he wants. This is truly Elon solving a problem only Elon has, by nuking a feature tons of folks use.
You can just make a new account... it's not like blocking someone stopped them from ever viewing your tweets again. Blocking was always just to stop viewing their tweets.