These aren't just recycled outtakes, they're new gags drawn specifically to let the cast mess up in ways the main series never would. The comedy lands hardest when you know exactly how seriously these characters take basketball, which makes watching them trip over their own egos feel like a private joke with people you've watched suffer through actual stakes. If you've already lived through Season 2, this is the show letting you stay in that world without pretending anything matters.
Kuroko no Basket 2 NG-shuu is a set of nine short comedy specials released in 2014 alongside the second season of the Kuroko no Basket sports anime. Instead of new story material, the episodes present animated outtakes adapted from the bonus pages of the original manga. They were packaged as extras with the home video release of the second season, in both the limited and regular editions.