Yes Its a good thinking to save bitcoin for children.May be in future the bit coin will be the main currency in the economy. and the other hand the value of the bitcoin might be very higher than now.Therefor the bitcoins will be a valuable property to transfer for their children like lands, houses ,business and etc.
Indeed, there is no need to share complete information with children about family assets. Let them work hard for their secure futures. It is though duty of parents to do some good savings for children but that does not mean we are going to share all with our kids.
I do agree with you that telling them about bitcoin and their future with bitcoin is going to affect their studies negatively. There are chances that they stop working hard.