Will freezing affect the quality of a dry-aged steak?
Dry-aging primarily breaks down the connective tissues in the muscle, naturally tenderizing it.  The concentrated flavor is just a result of the moisture loss that you've already identified.

Neither of these should be affected by freezing in any special way.  You'll want to be especially careful about further moisture loss, but as long as you properly package your steak for freezing you should be fine.