I think they mean, like, easter eggs. Things that only happen in ng+ or ng++. (Think of MGQ to MGQ ng+.)
What did MGQ do with their ng+?
Like the Angel Halo. It is a one-of-a-kind sword, but in NG+ when Alice goes to give Luka the sword he pulls out the exact same one. Also he starts with all the skills and tactics he had at the end of MGQ.
ah, overpowered start XD