Yes, with caveats:
1. CCIIO has proposed an age curve that lumps 0-26 into one age band, 65+ into a second age band, and 27-64 are 38 separate age bands. The 3:1 age band ratio, whereby the highest age band can cost no more than 3x the lowest age band, starts at the 0-26 band and not the age 27 band. This means that "kids" (is 26 really a kid?) will be part of the 3:1 compression, which means youth premiums will be dragged up quite a bit.
2. The blended average provided by KFF not only blends markets (individual, small group, large group) but it blends age as well. If I assume that the national uninsured population is, for the sake of age, demographically similar to the insured population, the blended average will not be affected solely by demographics. In other words, while the current blended average is $278 now, the 0-26 age band might be $225 and the blended 50+ age bands might be $325.