It does look hopeless and that the xylem and phloem parts that the tree needs to survive are gone. One can always wait and see. However, it does look like they got the inner bark as well as the outer. It may leaf out because the leaf buds were made in the fall and then drop its leaves because the way to feed them is gone. But as you can probably tell by my response, I tend to wait until I am sure a tree is dead.