This just happened to me on Friday. Concierge was waiting unexpectedly with a sign with my name when I got off of AC8538 (aka the a** end of the D gates), transiting to paid J AC880. Same nifty battery pack, and she escorted me all the way to the SS. Probably 3-5 minutes to get from the regional D gates to the SS, which sure was nice.
Weird part is I'm only E50K.