This video is dated January 12, 2015, but I think they meant 2016. The NJttW team (minus EJW) had a get-together one day before SeungGi’s birthday. It’s mostly an audio file they “discovered” on a staff member’s cellphone, but there’s also some video footage at the end.
Anyway, Na PD seems to be working very hard to promote the 2nd season. The re-edited version of the original NJttW will be broadcast on tvN at 9:45pm KST today.