To understand the lack of her presence Karlach's role in the game has evolved during development, possibly explaining her absence from early artwork. The artwork may be from an earlier version of the game where Karlach was not even recruitable.
While Karlach is part of the crew now and thus a replayable origin character, one could debate that Minthara and Halsin also could be included based on the fact that they can become part of your crew permanently at some points of the early game having an impact on the plot and be welcomed but that in my opinion is not necessary and fine if excluded or otherwise it could possibly open the path where everyone want their favorites included, line has to be drawn somewhere such as only inclusive to those we can pick as origin character.
Regardless is it still possible to have artwork updated to just at the very least having Karlach included now, what's your thoughts, should there be an update to the artwork before the game is finalized away from major updates?
It would help better represent the game and make it feel more relevant and professional, feels like the rug got pulled away too early.