Is it threatening any structures? I agree, that's pretty bad damage, on the other hand, hackberrys are tough old birds. If it isn't threatening anything, I'd just let it be. If you are asking if there's anything you can do about it, just let it be.
Included bark, this was always going to fail at some point, something to be aware of. An otherwise nice tree, I would pollard and try and save it!
Good luck