Nice tree!
It should mature and branch fine with the new leader. I've had to cut off the leader on mine before due to a similar thing and disease too, and the new one did great.
If the old broken leader is higher up on the tree with the new leader branch starting below it or if it is badly broken I would remove it. But if it just got bent down, and is now more like a branch and the new one looks like it is the main trunk of the tree, it should be fine to leave as is. Hope that helps!
