Yes, there is still hope. You are going to have to be patient. Keep it evenly moist, no drowning, no bone dry and wait. When you see new growth sprouting you will have your answer. That may not happen until next spring. Next spring you will get the final answer. Leave all remaining leaves on the tree. You may only pick up the ones that fall off on their own.

The more roots you got in the transplanting, the better the chances of survival.

It may or may not bloom next year. After all it has had an intense disturbance. But not blooming does not mean it’s dead. Not having any leaves would.

I wouldn't expect a Magnolia grandiflora that size to bloom for many more years, transplant shock or not.