I've had a lot of failures due to the same problem. Last year the Korean Giant scions I grafted bloomed and then did nothing. They stayed green until summer but were dead when I checked in November.
I took scions from a gnarly old Callery pear that has good fruit for deer. I'm not holding my breath, but I've seen Callery produce new growth from surprising places, so I'll try it anyway.
Your best bet might be to provoke new growth by giving the tradition a trim this winter if it won't bother whomever owns it.