I wouldn't worry about the old one, anyway - it's like a tree, it can take ages to grow a new branch - but it will
Yes some of the leaves on the cuttings will whither and die off, as long as the middle leaves stay green, they'll be fine as well
The new cutting I took in spring has just grown some new leaves in the middle, so they take a while.....I had new roots out of the bottom of the pots before I got new top-growth.