I know at that time in 2013 (the first Wednesday of February) we were in the parks and a similar thing happened.
HP rented out Hollywoodland and had a dinner or something there along with exclusive ride time of TOT, and it was closed from 6PM on. Then, after the park closed at 8, CM's rushed out from all over the place and set up a reception in Cars Land, and other things around the park.
The time-frame lines up, and with the Frozen Fun going on, they probably couldn't rent out Hollywoodland again to serve their purpose. My guess is HP's corporate party, again.