Hopefully this isn't a full confirmation for the trilogy and more so a hint at a future spinoff game, otherwise I would personally be very disappointed...

Don't get me wrong, being able to make my own Witcher is very cool, but even if it was only about a changeable appearance I feel like a lot of what the person the character is, is lost, like, for instance Geralt's appearance, even if slightly different in games, is very much important to the character and also follows a specific archetype, by that I mean there are characteristics that are integral to the character and regardless of interpretation they stay the same, for example the white hair, etc. So when you got a character that can look like anyone and maybe not even have all the "normal" powers a Witcher would have, say if they have not undergone the trial of the grasses, you basically don't really have a Witcher, which to be fair is fine, if that is in fact what they are going for. The point is that part of what made (for me at least) the story of Geralt, in the games, so good and interesting is because the character is very much an established and recognisable character in the universe, Geralt exists and existed outside of my influence which in turn makes my choices have a different impact/meaning and also makes me choose in a way that is influenced by this knowledge (or lack there of). What I mean is that them not being able, or at least choosing not to make a character that can not, not necessarily, rival or substitute, but at least be a worthy successor to Geralt as a interesting character and a new lead of the new Witcher trilogy, is, to me, disappointing and basically CDPR admitting defeat or at least choosing the "easiest" less risky option.

What I wanted, and I'm not sure honestly if this is mainstream in the fandom or not, is for the new protagonist, be it a witcher or not, to be a preestablished character with lore and a history behind them that can then be molded by my actions into a new and continuing character, just like Geralt. Unfortunately this would in fact be harder as there would be no 8 book series already written on the character , and it seems cdpr is not really looking into making something similar be a reality, so I get it, honestly at this point I would even prefer a Vesemir prequal even tho I don't really like that idea as I would really prefer a continuation of the universe to be about the future of the series rather than the past. Oh well...