I'm all for gore and a wide choice of fighting style, but I doubt fatality would fit in the game.
Look at the Splatterhouse remake, there were some kind of fatality there, and in the end, you just spend the whole game bashing enemies and doing the same fatalites again and again...
The "create your fatality" is good on paper, but just look at how shitty it worked in Mortal Kombat : Armageddon, I doubt CDPR could come with something better.
Something in the vein of "sneaking behind XXX and slicing his throat/breaking his neck" like in usual spy games would be perfect, no need to beat the guy to pulp with an useless animation, when you can give him a headshot or finish him with your rippers (some kind of wolverine's like blade), it's supposed to be and FEEL realistic, sure, if you killed a bastard who you wasted all your ammo over and screwed almost all your life bar, it's always good to be able to unleash your frustration over his dead body.
As much as i love Mortal Kombat, and fighting games in general, I love learning new combos, learning new fighting style, figure out how to tacticaly use a character in a combat, etc...
Cyberpunk isn't a beat'em all or a fighting game, no need for "combos" (or just a few attack button with some pre-made combos linked to a specific fighting style), usualy it isn't smart to bring your fists in a knife/gun fight, mostly when everyone wear a gun around you, except if they go in the Shenmue way:
Bringing a whole fighting system in the game, with combo, specials, balanced fighting style, etc... like a real fighting game (but still, Shenmue was done by the guys behind Virtua Fighter, so it helped a lot), If they're able to handle it, a system like this would be perfect, requiring some practice, more than stupid "1 button mashing", but I doubt they'll go this far.
Back on fatalities, I don't really see the point actually, sure gore have to be there, it's a part of cyberpunk, if I shot at point blank in someone's head, i want to see it explode, being able to torn an arm apart if I shot in it, even guts if I slice his belly open with a monoblade, you know, nothing "over the top", but realistic, just how ugly a bullet wound has to be, look at some video on the war, urban guerrilla, gang execution, usualy, they don't try to kill all "i-am-an-overstyled-badass", they know they risk their lives, it's nothing personal, it's just "blam blam" you get shot, you fall, you bleed, you die.
If the game is mature and want to have a "realistic, hard Sci Fi" vide, it would be nice to use the death in a mature way, instead.
It's not "Zelda" where you have to bash waves of monster who bleeds rainbows, or "Call of Mone...Duty", where you can shot a bullet in someone and no blood, no emotion, it's just so "bland".
Here it's the "real life" (well, you see what i mean lol), if you take a life, it has to mean something, not just "be my next target", but more "come on dude, you just killed an human being", the fatality is, IMO too much "for the show", it needs to feel raw.
In the pnp, it's well explained that real fight aren't like in the movies where two guys can make a gun fight with rocket launcher, here, you'd need to be scared to go fighting, pissing your pants as bullets fly by and when you shot the guy in front of you, it's not supposed to be "cool", but something ugly you had to do, when a cyberpsycho freaks out and goes on a rampage in a Mall, it's not "random NPC" who get killed, it's terrorised peoples, running for their lives and who'll end burned or hacked in a body bag.
Not saying i want to turn it in a "psycho" level of sickness, but just make it feel sick to end a life, we're so much desensitized with all those FPS, who try to make the death so "bland", like if it was a peacefull "game over" screen.
If Cyberpunk want to show a desesperate world where people are freaked out, and the world is a dangerous place, it has to be a cruel and sick place to be, when you kill someone, just the fact to blow his brain out has to have some "weight" to it, not just "congrat, you earn 10xp", just something reallistic, not over the top, so you can still make a rampage in the arasaka buildings, but keeping in mind you just shooting at peoples like you.
Well, that's how i see the "violence level" in cyberpunk, if it's too bland, all the "violent" side will go away, and if it's too violent, it's end in a cheesy gore-porn, It just need to find the right middle.
But Fatalities? I doubt it would fit in.
I'd be more in special animation if you kill someone with a special weapon, like showing him running as he burns alive if you shot him with a flammethrower, etc.... but no "forced animation" if you see what i mean.