that Abraham-ba(i)t-and-switch ...
Glenn used up all of his 9 cat lives in Season 6. He was the knight in shining plot armor.
Negan, as a standin for the showrunners, showing us that - once again - noone is really safe. They are running the show. Big, important gesture.
Cruel fuckin moment right there.
edit: also, gf and i watched Westworld and TWD back to back, and it's quite jarring that the human protagonists in those shows are going through pretty much the exact inverse of their respective situations.
In TWD, no matter how safe you feel, danger, death and loss is always looming right around the corner.
In WW, no matter how grim and shitty things look and feel, you can (for now?) always be sure that things are gonna be back to 'normal' the next day and that nothing of consequence will really happen to you.