My uneducated guess would be...since the 4.8is comes with the dual axle SLS system (option code S221A)...the comfort air shocks are used even though the sport pkg (S226A) is ordered. This would probably be for allowing the extended articulation of the dual axle SLS.
I didn't have time to check...but this may be the shocks that all e53s have that have option S221A & S226A. Anybody with these 2 options can probably verify this for us.