Reminds me of the long discussion of Star Trek transporters. Do they make a copy of you that goes on living your life, or are they really transporting your soul as well. There is no way to answer it definitively, that I know of.
I like that they left it open to interpretation, it allows the player to add their own headcannon about consciousness/soul/ whatever you want to call it. I would have liked to explore this more, I think transhumanism is a big part of cyberpunk.
Personally, I don't consider V to be dead, but he is not the same as he was before soulkiller. He is just different. I love the tarot in this game, and the death card on the side of Embers kind of confirms this - but its obviously quite open on how you interpret it. The location is very important for all the tarot cards in the game, and this one is no exception.
The text from the card is
Death is the card of becoming. It signifies an imminent and difficult transition – the conclusion of one phase of life and the beginning of another. Inevitably, something gets lost during the transformation, but something else will rise and take its place.
Notice it doesn't say anything about end of life, but instead a major, difficult change that will be take place. I interpret this to be the end of V (when he is hit with soulkiller) but the rise of the 'new' (post soulkiller) V. This transition is obviously difficult.
My personal headcannon here is also the Death card foretells the end of the 'old V' who wanted money, power, glory, etc in NC, and the rise of the 'new V' that sees that family and friends are way more important than money, power, glory. This is kind of symbolized when V lets the bullet necklace and all that it symbolized go in the Star ending. He's gone through a difficult transition, and but that life is gone. Now though, he has a new life with family.
Expanding on this a little more, I also believe the tarot fortells that V will find a person of great strength who will save V (Panam, the strength card is right next to where you first meet her), and that the tarot also says that your only hope is to leave (The Star card is on the radio tower just outside NC, where you get into the baslisk with Panam for the last time and leave NC.) This is my mind makes Cyberpunk an epic story about fated lovers (the tarot is powerful in the context of the game) who save each other from the world, at least if you play male V and romance Panam. I personally loved this, and it wasn't at all what I expected when I got the game. This is why I think the Star is the best ending - even when I replay I won't be able to do the other ones.
I wonder if you could do the same thing for the other LI's or endings, I haven't figured anything out, but my headcannon is already set.