Due to the large rootsystem. i think all grafts that heal will leaf out and grow a shoot.
However the top grafts will likely grow longer shoots, and outcompete the lower branches.
You can fix this with more prunning on the top branches. (not just pruning shorter in winter pruning. But pruning more often. IE summer pruning to)
You see this with espaliers. You want your bottom “tier” to be 2-3 years older than the next one. To keep it balanced.
If you prune the top of the tree often and heavy you should be able to reach the same effect. If it’s worth the extra effort is up to you
If you can easily get the variety on top again. or already have it on another tree. Id prune the top off.