IAH Parking Garage, Term A/B

Went to airport around midnight last night to pickup my wife. For many years I have always parked in the garage and waiting in baggage for her to arrive. Last night I was informed that the garage is closed from 10p-4a and only available to employees and departing passengers. The young lady told me there were limited spots, but you could see on the board that there were at least 300 available spots. When did this non-sense start?