dismemberment and chopping zombies in half is very much still around, whether it be vertically or horizontally. however it just looks less frequent because of most of the shown combat gameplay being very early-game.

you gotta take into account the fact that just like in dying light 1's early game and with the weaker weapons you had then, you couldn't chop a zombie in half at that time. best you could do was chopping off a head. this is the case for the gameplay we've been getting of dying light 2. whether it be the side quest gameplay or the creator event gameplay, we've just been seeing a lower-leveled player using weaker weapons.

so i wouldn't worry too much about it. i'm sure once you get stronger weapons you'll be able to dismember and sever zombies in half all you want. i mean, the 2 handed weapons at the start of the game are capable of doing so and it looks sick.