If those trends in health status and age hold up among the people who actually enrolled—and who will ultimately enroll—it increases the likelihood that insurers will not have to raise premium prices excessively next year to compensate for a bad risk pool that comes from having too many sick and old people signed up.
The early breakdown according to age and health of enrollees in the ACA will be one of the important factors that is used in evaluating its immediate success. I say immediate, because the requirement that everyone sign up should eventually bring the demographics into line no matter what the early breakdown. However, in the interim, opponents will make as much political hay as they can if the demographics trend too much toward the aged and the unhealthy.
Of course the ultimate effect of bad demographics would be higher premiums which would obviously affect the acceptance of the ACA. The more young and invincibles who enroll, the better the pools, and the lower the premiums for everyone. So the results of this early survey have to be viewed as very good news.