I am not sure we have anything like the level of statistical data necessary to answer this specific question precisely.
But it is worth noting that the policies that targeted the disabled killed maybe 100,000-400,000 people. That is a large and horrible number. But it also took place during the context of one of the bloodiest wars in documented history. Germany itself suffered some 5 million dead soldiers during the war, and probably many more than that were injured. Similarly the civilian rates of injury and dead were in the many millions. So it is hard to imagine that there was any net "loss" of people with disabilities, given that the war itself likely created many millions of people with new disabilities, both physical and psychological. It may be that the categories of disability were briefly altered — e.g., if the Germans killed off most of their people with Down's syndrome, that would be a persistent change until a new generation came about. But the overall rate of disability in Europe was surely higher postwar than prewar, and ultimately the Nazi efforts to kill the disabled would have no long-term impact on the number or even type of disabled people in Germany or elsewhere.