The idea here is that consciousness is a force. All thoughts created become things in a sense, and the energy projects outward. Because all energy seeks its target, there will be a healing intention with no place to go. So the reason for it to be repurposed is simply to harvest the energy it contains and apply it to something useful. There are always people being prayed for but through prayer that falls short in some way, either through inadequate belief in the Divine or inadequate belief in the self of the one launching the prayer. The divine realm can use the energy of a prayer request that is no longer needed for its intended target and repurpose it for receipt by and delivery to another. This is perfectly appropriate and in keeping with the reality that the human collective and its members are a vast interconnected web and all share a common origin and destiny. So this is not us taking charge, but merely filling in the blanks desired by human agents, although perhaps at different times and places, making requests that then ultimately converge when the energies are available to bring in additional healing, courtesy of a requester who may be overdoing things but nonetheless doing a good deed in the process, as nothing is wasted.