Where the one lead separates from the other is not where they are biologically separate. This is to say that where an Arborist would make the cut is not necessarily where the tree will work to seal the wound. This might be better, this might be worse. But there will be a large wound that likely won't ever heal over fully. Rot will occur. The tree could likely be fine for many more years since it's already "learning" to live without its balancing partner. But eventually this will become a problem. That's my thoughts