What happened to Kaneki in episode 12 of Tokyo Ghoul:re?
The metaphor is that Kaneki is putting Haise to sleep, as now Kaneki has taken over by regaining his memories. Haise will never come back, as he has become a part of Kaneki. The 'cliffhanger' now is how will Kaneki act around his friends that Haise made, and what will he do next.